freeFTPd

freeFTPd is an implementation of a FTP / FTPS / SFTP server that aims to offer users a stronger level of encryption in order to prevent breaches inside an unprotected network.
Much like other similar servers, freeFTPd is able to provide users with a method to access remote resources in a secure way and targets TCP / IP networks in particular.
The installation process is fairly simple and effortless; the only intervention required on the user side is needed at the end, when you will be offered the possibility to install the program as a system service as well.
Concerning its appearance, freeFTPd adopts a rather plain interface, but despite lacking eye candying elements, manages to remain intuitive. This is because of the well-structured set of components that are carefully organized in sections and placed into a sidebar.
The first of the tabs displays the status of the server, which will be offline in the beginning, because none of the configurations has been completed yet. It is possible to use both FTP and SFTP servers at the same time, if they are setup properly.
The configuration dialogs for each type of server are very similar, requiring that you provide the IP address to be listened, the port, the root directory, as well as the maximum number of connections.
The encryption part is done through certificates (for the FTP server) and RSA or DSA keys (for the SFTP server), which are generated by default at application startup.
Other highlights include the possibility to define a list of host restrictions and virtual directories for use with the server, as well as to customize logging options.
In conclusion, freeFTPd is fairly easy to use, especially for users who have previous experience with FTP and SFTP servers. The traffic is encrypted, which eliminates most of the threats associated with such implementations.