Debian is a Unix-like computer operating system that is composed entirely of free software, most of which is under the GNU General Public License.

PuTTY is an SSH and telnet client, developed originally by Simon Tatham for the Windows platform. PuTTY is open source software developed and supported by volunteers.

wxWidgets is a C++ library that lets developers create applications for Windows, Mac OS X, Linux and other platforms with a single code base.

Modern, powerful open source C++ class libraries for building network- and internet-based applications that run on desktop, server, mobile and embedded systems.