CrushFTP is described as 'robust file transfer server that makes it easy to setup secure connections with your users' and is an app in the File Sharing category. There are more than 25 alternatives to CrushFTP for a variety of platforms, including Windows, Linux, BSD, Mac and iPhone. The best alternative is OpenSSH, which is both free and Open Source. Other great apps like CrushFTP are FileZilla Server (Free, Open Source), Microsoft IIS (Paid), vsftpd (Free, Open Source) and ProFTPD (Free, Open Source).
OpenSSH is a free version of the SSH connectivity tools that technical users rely on. OpenSSH encrypts all traffic (including passwords) to effectively eliminate eavesdropping, connection hijacking, and other attacks.
Internet Information Services (IIS) for Windows® Server is a flexible, secure and easy-to-manage Web server for hosting anything on the Web. From media streaming to web application hosting, IIS’s scalable and open architecture is ready to handle the most demanding tasks.
Syncplify.me Server! is the free FTP, FTPS, and SFTP server for Windows by Syncplify, Inc. Powerful, secure, yet very easy to configure, this software simplifies regulatory compliance and operation of a secure file transfer server.