Natural Reader is a professional text to speech program that converts any written text into spoken words. The paid versions of Natural Reader have many more features.
eSpeak is a compact open source software speech synthesizer for English and other languages, for Linux and Windows.Discontinued
The last version (1.48) is from March 2014.
NextUp.com develops Windows text to speech (TTS) software applications like TextAloud that let your computer talk with AT&T Natural Voices. TextAloud can also be in Microsoft Word as a plug-in.
Simple TTS Reader is a small clipboard reader. Simply copy any text, and it will be read aloud. You can choose any installed speech engine, e.g. Microsoft Anna. This text-to-speech utility can also be minimized to tray.
The program is no longer updated. Last version, 1.2, released in October 2010, can be still downloaded from the official website
Online Text to Speech by ReadSpeaker. Speech-enable web sites, mobile apps, online documents and forms so that your visitors can listen to your content.
Speech Central is a feature-packed, text-to-speech software with years of development history culminating in an easy-to-use tool that just works. Start listening, pause and pick up where you left off later. Easily build a knowledge base and convert read text to MP3.
Don't spend your time in front of the screen reading articles when you can listen to them. Pack them as MP3s on the cloud, USB drive or any folder and then access them in your car or on your mobile device.
Let Text to Speech read web pages to you. Download webpages for reading offline. Practice speed reading. Use it simply as a RSS reader or use RSS playlists feature to listen to items in RSS feeds. Read from clipboard. Offline playlists.
A web app that let you create voiceovers for your videos. Upload a video or use a youtube video link and add a voiceover to it !