For additional software some excellent sources of free and open-souce software
are
• Tucows a downloads site with freeware, shareware, open-source as well as
commercial software. It has many mirrors all over the world for speedy
downloads from local servers.
• Download.com similar to tucows
• SourceForge a site featuring many OpenSource projects. You can start
your own, or get software for almost every need. Most projects have GNU
and Windows versions. The mirror system isn’t as large as Tucows, but
you can still usually get a mirror on the same continent.
• Table of equivalents can be useful if you want to know more about specific
programs when changing from windows to GNU or vice-versa.
Of course, it is also possible to buy copies of software, particularly for the
Windows operating system. To be fair, the library of proprietary software
available for Microsoft Windows is the largest and most comprehensive body
of software in history, while that available from the open source community is
increasingly varied and mature.