Browsers like Chrome and Safari are closed source. Chrome is popular, but is part of Google's wider efforts to spy on users by recording a lot of what you do online. You should choose an open source browser that respects your privacy more.
Privacy-enhancing software I trust / recommend. Browsers and their extensions, email providers, VPN services, note-taking apps, passwords managers, backup, sync and encryption software - to name just a few.
Browsers like Chrome and Safari are closed source. Chrome is popular, but is part of Google's wider efforts to spy on users by recording a lot of what you do online. You should choose an open source browser that respects your privacy more.
Firefox is the most fully-featured open source browser available. In late 2017 an update increased the performance of Firefox to make it much faster than Chrome. Firefox is also the most configurable web-browser (via the about:config menu), and has a huge number of extensions. Most importantly, it is not built from the ground up to spy on you.
Brave is a relative of Chrome but built from the ground up to protect your privacy and anonymity. It's open source and has ad-blocking, tracking and fingerprint protection built in directly (check the "shields" menu). An excellent project.
Tor isn't like a normal browser. It redirects your traffic through three layers of servers, so that it's extremely difficult to tell where in the world you are when you're accessing something online. Some websites are only accessible through Tor. It's slow, but does a great deal to protect privacy, as long as you follow advice about how to use it wisely.
Most browsers can have their functionality extended to protect your privacy online. Here are a few of the best.
Websites track everything you do and advertise to you all the time. uBlock Origin is a free and open source browser extension (all major browsers) that blocks all that stuff. Because it blocks ads from loading, you use less data (pay less for it too, perhaps) and the internet becomes faster. Developed by the Electronic Frontier Foundation, who fight for your online privacy rights, amongst other things.
Control your cookies! Auto deletes unused cookies from your closed tabs while keeping the ones you want.
Protects you against tracking through "free", centralized, content delivery. It prevents a lot of requests from reaching networks like Google Hosted Libraries, and serves local files to keep sites from breaking. Complements regular content blockers.
If you connect to a website via http only, the traffic between your computer and that website is visible to others. If you connect via https, it travels encrypted and is very difficult for outside people to spy on. Many websites have both options. This browser add-on ensures https is used wherever it's available. (Hint: https connections usually give rise to a little green padlock symbol to the left of the website address in your browser.)
Popular search engines like Google and Bing! are outrightly hostile to privacy. Google's entire business model is based on recording everything you search for to profile your life. They use this information to make money through targeted advertising. As a result, they know more about their users than a full-time person following them around would. Beware privately owned "free" services: you are their product. Here are some search engines that don't track you. Don't get impatient too soon: they're not as accurate or personalized, but you can learn to combine them to replace the likes of Google almost entirely.
Start page actually gives you Google results. They anonymize your searches so that Google doesn't know it's you that's searching. So overall: Google levels of accuracy, except for anything that's location-based.
DDG is a privacy-focused search engine that does particularly well for US- and Canadian users. They are huge champions of privacy, support many excellent privacy-related causes.
If you want a quick guide on what is wrong with common search engines, like Google, visit DuckDuckGo's own page on the topic over at donttrack.us
A meta search engine (it aggregates results from other search engines). Free, open-source and doesn't track you or collect data that violates your privacy.
Qwant is an ambitious French project to offer a Google search alternative. It's private and closed source, but promises and seems not to track its users. It makes a solid contribution to the mix of privacy-respecting search engines required to replace Google's power.
Gmail's business relies on selling out your privacy to advertisers (same as Facebook), they don't store your data securely, and they don't support encrypted emails because their business model depends on being able to read them. They let third party developers read them too. If you use Gmail, you have no email privacy; quite the opposite. Yahoo are just as bad in another way: all 3 billion of their accounts were exposed for years and Yahoo did nothing even to alert its users to change their password. Gmail, Yahoo and Outlook also comply with government surveillance; they can be forced to give away your emails and other private data and can't even tell you about it. Such services are not "free"; they are part of a surveillance apparatus used for their private profits and government spying on private individuals. You pay with your privacy. Here are some alternatives that help against this.
A Swiss email service that encrypts your inbox so that governments, hackers and not even Protonmail themselves can see it, steal it, use it to profile you or sell it to others. You can send encrypted emails to both Protonmail and non-Protonmail users (the latter via pre-agreed passwords). Being based in Sweden puts PM outside US and EU law, meaning they can't be forced to give up any user data to outsiders without Swiss court approval - an extra level of confidence inspiring protection. PM offers 1GB free accounts. Paid users get to use their own domains and Bridge, a Windows, Mac and Linux app that lets you sync your emails locally to an email client (e.g. Thunderbird, so you can search it and back it up.
A German email service that encrypts your inbox so that governments, hackers and not even Protonmail themselves can see it, steal it, use it to profile you or sell it to others. You can send encrypted emails to both Tutanota and non-Tutanota users (the latter via pre-agreed passwords). Perhaps Tutanota's best feature is their search: despite the privacy-enhancing encryption, you can still search your emails by body text. Amazing.
Feature-rich email, calendar, contacts, notes, (simple) file storage and even document processing based in Germany. Email encryption (via PGP), 2-factor authentication (inc. Yubikey) makes it a particularly attractive service. You get the choice whether you store your encryption keys or they do. Hugely more private than the likes of Gmail, but not as secure as Protonmail. An excellent compromise.
When you send a normal SMS message from your phone, it travels through the air in plain text. Everyone from your ISP or mobile phone provider, the mobile phone mast owner (or those who install fake mobile phone masts - a huge industry), hackers and government agencies, can intercept your text and see who is talking to whom and what about. Apps like Snapchat, Google's "Allo" and so on permit their parent companies to view messages between people to. Their servers can be hacked, and the contents of the messages revealed that way. Governments can also subpoena companies like Google to give them information on what messages have been exchanged. The answer is encrypted messaging apps. Here are the best.
A free, open-source way to send end-to-end encrypted SMS messages, pics and voicemails via mobile, Windows, Mac or Linux. You install it and forget about it, but mass surveillance programs can't read the messages you send. If you heard that WhatsApp is encrypted, you're right: they do it using Signal's protocol. Except that Signal implement it in a much more secure way.
Slack enables teams to communicate with focus email doesn't provide. But Slack isn't private: the messages aren't encrypted: Slack can read the messages, so can hackers who breach their servers and so can the US government, who can force Slack to give them information on what Slack users say. Encryption is the answer. Here are the encrypted Slack alternatives for your team.
Based in Germany, Stackfield offers end-to-end encrypted Slack-type functionality. They can't read what your team is discussing, can't give it away and even successful hackers won't be able to make head nor tail of it. Stackfield is good for sharing messages, files and even calendaring across projects. Their support staff are also very responsive.
An open-source, end-to-end encrypted (private/secure), affordable Slack-type way to chat via chatrooms/channels, manage team projects, share files, etc. Available on Windows, Mac, Linux and Mobile. Well-featured free version.
You should be using a passwords manager. You passwords should be long and very complicated and never based on dictionary words. Password managers help you remember these so you don't have to. But because of the security implications, you want the most trustworthy password management software possible. That means going open source. Popular solutions like LastPass, have all kinds of problems. For a start LastPass doesn't encrypt the domain names their users have accounts with, which means they can be profiled. Here are are the best password managers I know (and use!) that respect your privacy, not just your security.
A free, open-source, end-to-end encrypted password manager with strong features and that syncs your passwords, notes, attachments between devices, including mobile. It's easily the best LastPass-like service, except that it encrypts everything, which LastPass does not. Bitwarden is easy to use, supports various 2-factor authentication methods and has excellent browser plugins. The developer is extremely responsive. The paid version is only $10/year, which means it's better value than LastPass, Dashlane and the others. Bitwarden is an absolutely excellent offering.
The best cross-platform, open-source, offline desktop password manager (if you want sync, you have to use another service, like Tresorit or Spideroak). Very consistent experience across Windows, Mac and Linux and compatibility wtih several mobile apps.
An open-source and free password manager by the people behind SpiderOak. It syncs your database between Mac, Windows, Linux and mobile. It's also very simple and very easy to use. This is the password manager to recommend to people who aren't too comfortable using computers, perhaps.
Normally, you type in your username and password to gain access to most online accounts. A malicious hacker's job is to figure out what these are. The username is easy: these days, 90% of the time it's your email address, and that's almost trivial to guess or steal. The password is harder, but not that much harder: if you don't use something strong, you're at risk. (Hint: use a password manager - see above.) But here's the thing: your username and password are things you KNOW. A second level of security would be something you HAVE (that a hacker wouldn't have). Options include: a phone app that generates a unique code on YOUR phone (and no one else's), or a physical object that generates unique, one-time passwords for you (e.g. a Yubikey). This is called "2-factor authentication", or 2FA (2 factors = something you know and something you have.) For security, you should have 2FA enabled for as many of your accounts as you can. Below, I list the most trustworthy options for 2FA for securing your online accounts with maximum convenience.
A small USB device that plugs into your computer. There's nothing to install: you just press a button when asked and it delivers a unique code used to authenticate you when logging into many different websites and services (including Gmail, Fastmail, Mailbox.org, Facebook, Bitwarden, LastPass, Dashlane, Tutanota, Keepass, MS Windows, Linux). Extremely durable and easy to use. Most services allow you to configure multiple Yubikeys (a good idea), you can use the same Yubikey for different services and you can even share them with trusted people (in face you lose it). It's a brilliant way of improving your online security.
If you use Google Authenticator on your phone, why not use this open source app instead? It does the same thing, but doesn't come from that nasty, privacy-disrespecting company. Works the same in all other respects, however.
Google Drive, OneDrive, Dropbox, Sugarsync, iCloud, Box.com are subject to mass surveillance, and at least Google's case, make money from trawling through your private content for information to profile you and sell to advertisers. Where will that data be in 20 years? Who will incriminate you, dox or blackmail you or increase your insurance premiums based on what they know?
The way to prevent this is to stop letting others access, view and analyze your files. Do this with time-proven cryptography and do it today.
Cryptomator creates and encrypted version of your data in a "vault", which you sync to the cloud using any service you like (even Dropbox or Google Drive). You can generate many such vaults and use them with different services, as you like. On your computer, they are ordinarily locked in a way that makes them inaccessible to anyone without the password. Cryptomator is free, open source and uses time-tested, reliable cryptography. It's the easiest way to add privacy to your existing service.
A Swiss, Dropbox-like service that syncs your files across Windows, Mac, Linux and mobile with zero-knowledge encryption, 2-factor authentication, and strong features. It's expensive but might be worth it; even Tresorit cannot see your data and it doesn't sit on their servers in any way that a hacker could make sense of, even if they did break in. The technical implementation of Tresorit's security is particularly impressive, and superior to just about any other service I know.
A Canadian, service that very much resembles Dropbox and its functionality. It uses end-to-end encryption to provide waaay more privacy than you get from Dropbox, Google Drive, Box.com, Sugarsync, iCloud, etc. Works on Windows, Mac and mobile (not Linux). Attractive pricing.
What: A VPN provider. Makes your online browsing much more anonymous.
Why: Without a VPN, your ISP (internet company) knows everything you do online and can track and sell info about your every move. In the US it became legal in 2017 for ISPs to profile their customers and sell their private data to the highest bidder. So if you searched for "nasty rash", every advertiser out there might know that. Using a trustworthy VPN will keep that information from your ISP. Private Internet Access are one of the most trustworthy out there (for too many reasons to mention here), they don't keep logs and in 2018 have promised to open source their code. They are also cheap. A good alternative is [ProtonVPN].(https://www.alternativeto.net/software/protonvpn )
What: A Swiss VPN service run by the folks behind ProtonMail. It's on the pricey side, but it's one of the better, more trustworthy services out there (important!) and you get a discount if you buy it with a premium ProtonMail account.
Why? A VPN helps you keep your internet activity hidden from the prying eyes of ISPs, who can sell it (in the US), or be forced to give it away to governments who want to profile their citizens. If you're not using a VPN, your ISP knows everything about what you do online. A VPN can also be used to appear as though you're in a different country, which can be useful for going around location-based restrictions.
What: A DNS service. When you type in "www.whatever.com " , it figures out how to convert that into computer speak and connect you to it.
Why: 126.96.36.199 are owned by Cloudflare. Their technology makes 188.8.131.52 blazing fast. Moreover, if you don't use them, you're using either Google's DNS servers or the DNS provided by your internet company. In that case, everything you search for is being tracked and can be sold to advertisers. Cloudflare promise to delete all records of what you've been doing online within 24 hours and never to sell it. Oh, and it's free, just see the instructions page: https://184.108.40.206
What: An encrypted, zero-knowledge productivity app that's about as good as Evernote for key note-taking functionality, but with much more security and privacy.
Why? Because Evernote, OneNote and their ilk don't store user data in a secure enough or privacy-respecting way, are under the jurisdiction of the NSA and FBI who can subpoena your notes and data without telling you, and because they don't offer Linux clients. Cryptee offers a lot already, and it's only very fresh to the game. Check it out!
Open source, markdown-based note taking that syncs to desktop and mobile. Crucially, your notes are encrypted with a password only you have, so Standard Notes, governments and hackers can't read them. The paid version allows you to extend functionality through a growing list of add-ons.
What: A very promising, multi-platform, open-source (and free!) markdown-based note-taking app.
Why? On Mac, Windows and Linux, Boostnote stores your data in any folder you designate, which you can then sync using whichever service you like (see below for syncing software). So you can have your notes everywhere, using end-to-end encryption. It also has tagging, instant search, cross-note links and code highlighting. It's open-source, trustworthy and developing quickly. Syncing to mobile needs development, but Boostnote is the best note-taking app I know so far.
Veracrypt can create encrypted containers for files or even encrypt whole hard drives or USB sticks. This is so no one except you can open and view the contents. It is built on the old TrueCrypt project, which was very popular. Somehow people are still recommending TrueCrypt (even though it's outdated), even though Veracrypt is newer, has had a number of security audits and improvements and has had more functionality added. It is an excellent, free and open source project run by academics in France.
Enter a password and your mounted (opened) contained or drive behaves just like any other hard disk on your system (e.g. copy/paste files with no noticable lag.) You can choose from various different (or even multiple) encryption protocols. You can even create hidden containers so that you can deny your secrets exist, even to authorities. One password opens up a drive with boring files, a different password opens your secrets. No one can prove the one with secrets even exists. Very clever. (This is called "Plausible deniability" under US law; read about it on Veracrypt's webpage.)
Veracrypt is for protecting data from prying eyes (e.g. so that no one can read it of your computer is lost, stolen or confiscated) or if your kids go snooping on your computer. Know, however, that encrypted containers are not good for syncing data; for that you want something like Cryptomator (or a service like Tresorit, Spideroak or Sync.com). These and Veracrypt complement each other, so you can (and probably should) use both. Veracrypt works on Windows, Mac and Linux (and probably BSD, I should imagine.)
Need to send files from one computer to another beyond what your sync service offers? The key to protecting your privacy is to use encryption and trust as few people between the two computers in the transfer as possible. Here are some options.
What: Free and open-source way to send large files to another person privately without anyone else's servers in the middle storing your data. Both sender and recipient should be online at the same time.
Why: Easy to use, allows larger files than email, makes it difficult for anyone else to see what you are sending. Files are transfered using SSL encryption.
Also consider: Syncthing (especially if you have many files to transfer)
Install on two devices, and type in the codes. Then wait a bit whilst it comes to its senses. Once it's ready, you can transfer files between the two devices at very fast speeds (I got up to 90 MB/s on my own Wi-Fi network, but you can do it between two computers in different locations. The file transfer is encrypted by SSL. Syncthing is free, open source and multi-platform, although it's very slightly counter-intuitive for beginners. But not in a way that should stop you trying it.
I was very long winded in answering you the first time. Think of it like this: Sync.com is a massive security and privacy improvement over Dropbox.
It's like this: If Sync.com is lying, they're offering you the same security as Dropbox when they are telling the truth. If Sync.com is telling the truth, you're WAY better off than with Dropbox. Therefore, Sync.com is a much better choice for both privacy (the company can't spy on your files) and security (they can't lose your stuff to other people).
So I would get Sync.com, get rid of Dropbox and move on to make improvements in other departments. (e.g. email, VPN, stop using Chrome, get browser add-ons, Skype replacements, and so on).
Glad to see that your back! Have been missing your comments / reviews. Nice that you found the list feature!
[Edited by Ola, March 25]
Thanks. Nice to be back.
Your question concerns two things: to what extent we should pursue privacy and, more specifically, how good is Sync.com for your privacy?
Let me take Sync.com first. You're right: it's not open source. Ideally, it would be, so that everyone could inspect their code, which is the foremost source of trust. However, how 'good' for your privacy Sync.com depends on other things. So whilst it doesn't score open source points, it scores big in other departments. Assuming you can trust what they say, Sync.com give you zero-knowledge encryption for your files. That means files they backup/sync for you are visible only to you. Not them. That's a GIGANTIC improvement compared to services like Dropbox, Google Drive, Sugarsync, OneDrive and so on. The principle behind this is that Sync.com's software encrypts your stuff on your computer, with a password that ONLY you have. They don't have it. Dropbox and those other guys, by contrast, encrypt your stuff on their servers with a key that they have. And can share. And so they can look at and lose your stuff, or be forced to give it away to government authorities. So Sync.com don't score big on trust (which is not to say they're lying to you), but they score big on the MODEL that they use, and that's a big advantage over these other companies people usually go with. So compared to Dropbox, Sync.com are hugely preferable.
But now comes the harder thing to consider. Sync.com have clients for Windows and Mac only. Not Linux and BSD. And Windows and Mac are proprietary, closed-source operating systems. That means you can't check what they're doing to your data. Because of this, it's POSSIBLE that, whilst Sync.com is protecting you to the max with their great encryption model, your operating system is leaking information left, right and centre about what files you're storing. That can happen in many ways. For a start, Microsoft or Apple could be keeping a record on what software you've got installed on your machine, including that you have Sync.com. Microsoft has also an absolutely disgusting practice in Windows of keylogging, by default, EVERYTHING you type. And yep, that includes that all-so-secret password you're using for Sync.com. You can switch off the keylogger in the privacy settings, but how do you know they are really switching it off? You can't check the code (Windows isn't open source), and maybe US law-enforcement told them to keylog anyway the inputs from people who have Sync.com installed. After all, maybe those are the people trying to hide something with encryption. Follow my drift? Apple are no more trustworthy. Just a couple of years ago, their DESKTOP search engine reported everything you searched for back to Bing (a Microsoft product!). More recently, that's gone to being a Google collaboration.
So now I have you worried.
Because you're considering Sync.com I know you're a Windows or a Mac user (or both). Are you better off using Sync.com than, say, Dropbox? Absolutely. Does it protect you from the very nature of your operating system? No. Not at all.
I don't know your computer or privacy requirements. I would always urge you to ditch Apple and Windows in favour of Linux, if you can. I know that, for various reasons, not everyone is able to do this. (I have this problem at work, for example.) Ultimately, Sync.com is a reasonably priced service that encrypts your data and that alone makes it miles better than Dropbox. Give them your money, not Dropbox.
It's something like this:
Win/Mac + Dropbox < Win/Mac + Sync.com < Linux/BSD + a proprietary service (e.g. SpiderOak) <<< Linux/BSD + an open source service
Ok. So what about the Canada thing, right? Is it a problem? Well, I can't pretend to be a lawyer. But I trust in mathematics much more than in laws. Laws can be bent, mathematics (read: good encryption) can't. That's the essence of it. It "feels" to non-experts that US-based businesses must be the worst for privacy, but actually, there are US laws that allow US agencies to spy on the data of foreign (non-US) nationals but not US nationals. That puts data in Canada at greater risk. But it applies the same to Iceland and Switzerland too. On the other hand, Canada willingly participates in the Five Eyes program, so perhaps your data isn't safer there than it would be in the US anyway. I guess what I'm trying to say is that jurisdictions mean much less than encryption.
Perhaps you're wondering what I use.
I use: Linux as my OS and Tresorit as my syncing service. It's not perfect. Tresorit is not open source and it's terribly expensive. But it's hosted in Switzerland and they support Linux. Now, I know that's an expensive solution and I think that won't work for everyone. What if I had to get cheaper? I would go with Linux + Mega OR Linux + SpiderOak. If I HAD to stick with Windows (shudder) I would consider Sync.com as good ad Tresorit, except for the legal stuff, which I think is a minor consideration.
I hope that helps. Let me know if you need any more specific help or clarity from me. Glad to hear you're taking your privacy into your own hands!
Well-researched, informative and ample list from a trustworthy source. Thumbs up, John!
One question, on bitwarden's entry, you don't mention Encryptr. Do you still recommend it as a good password manager alternative? Cheers.
[Edited by carmelapedinni, April 19]
Encryptr meets some of my favourite criteria: open source and good encryption. (It's made by the folks at SpiderOak.)
However, Encryptr is very simple. It lacks two-factor authentication (2FA), so that makes it less safe (or as safe as Bitwarden without 2FA on). You should aim to have 2FA if you can, particularly for important things. Encryptr has no browser plugin, and so you have to copy/paste your login credentials into a browser. Generally, it's not the best idea to have passwords stored in your copy/paste clipboard as, in principle, that could be read by mailcious apps.
I would say that Encryptr is best to recommend to people who are really not used to using computers (e.g. my grandma); few apps are simpler. It's better to have than nothing, but it doesn't have enough features for me. But it's free (as in beer) and you can just download it and play with it for 10 minutes to see if it's for you.
Thanks so much for the through answer. I've been using Encryptr for a while now but I'm also missing some of the features you mentioned, especially on mobile. I'll definitely look into your other suggestions, then! Cheers.
As usual a very thorough and educational response, thank you!
Yes, I'm using Windows, and yes, I've been using Dropbox for quite some time now. I want to change that. But it seems the more you read about it the harder it gets to make a decision, with so many things to consider. I've been wondering too about country jurisdictions and ultimately I have to agree with you: your money should go where numbers are solid. On the other hand at some point you are just going to have to trust on someone else and take their word for it, there's just no way around it, and so again it becomes really hard to make the right choice. Regarding Sync.com is just a bit strange to me that they would open up their source code in the browser but not in their desktop/mobile clients. I'm not an expert in the subject and I'm sure there must be a good reason for it, but the way I look at this is like building trust on uneven ground.
In any case is always good to know that there is an alternative even if you have to work a little harder to get to it. I really appreciate all the effort you are putting into making this list, commenting and explaining so clearly this type of things that go over our heads for the most of us. Cheers!
I have tried Joplin. I think it's a good app. I had it in this list before, but prefer Crypt.ee. But there's nothing wrong with Joplin.
Calendaring is something I am so angry about, you have no idea. Absolutely no privacy-oriented service provides a fully-featured, synced calendaring option, despite it being the back-bone of many people's online work flow. The closest thing used to be Countermail's calendar, which was zero-knowledge encrypted and built into their webmail interface. Then, inexplicably, they removed that after some UI "improvements".
Both Tutanota and Protonmail have been promising an encrypted calendar function for a very long time, largely in response to customer demand. Tutanota have, year after year, postponed the development of their calendar, invariably prioritising other features. Users there are very unhappy about it. Protonmail claim to have started work on their encrypted calendar with no word on what features it is to have. They claim they'll release an early version at the end of 2018. The gap between launching "Gmail replacement" services and offering a private calendar ought to be narrow, but it seems the geeks working for these services prefer working on other things first.
So what's left?
There are only a few options I know that even come close to fixing the privacy-calendar problem. Some of these sync between platforms using their own app (e.g. Fastmail), others rely on third-party open-source apps: you'll have to explore this yourself.
A start-up called Secure Swiss Data is in the process of raising funds for launching what looks like an intriguing encrypted calendar option. They're active online through social media, but I haven't seen any commitment to dates and I can't vouch for them as I haven't tested what they have on offer. Worth keeping an eye on.
I hope that in there somewhere you can find the calendar that suits you. I presently use Fastmail's offering and will switch to Protonmail if and when they release what they've promised. Good luck!
[Edited by JohnFastman, July 28]
Hi John, I've been reading quite a few of comments/reviews from you and I have to say that I'm really impressed with the effort that you put into explaining things and pointing out not-so-obvious facts/news. I'm already starting using many tools based on your recommendations so thanks for that! I wanted to ask you however about Sync.com: how come it is included in this list while is based in Canada (are there any privacy concerns)? I also couldn't find a lot of information about it being open-source (only about their browser version). Otherwise it looks like a great service but I wanted to ask you directly about it, if you don't mind.
Thanks a lot, cheers.
I would add joplin notes as a note taking app. It has sub folders and sync and the webclipper does the job. My only gripe is that pictures can't be pasted.
Also, what would you recommend for syncing calender. I am currently on google as I need an option that syncs between my apps on mac and android.
Great list! I personally think you should include Myki Password manager on the list among others. It seems extremely on the side of privacy, storing your encrypted passwords on your device like keepass but using a LAN type of sync, so they dont store anything and nothing passes to their servers.