Word-to-LaTeX - April 2005 - June 2006,
program for converting documents written in Microsoft Word into LaTeX and XML format (additional formats can be easily added through the configuration).
It's implemented in C# language and uses Word Object Model. Word-to-LaTeX runs only on Windows with Microsoft Word installed.
More details.
mkrss - March 2005 (Linux port in September 2006), RSS feed reader written in C++, supports RSS 0.9x, RSS 1.0, RSS 2.0. May be used in both
Linux and Windows. More details.
htmltolatex - August 2005, program for converting (X)HTML pages (including CSS) into LaTeX format (or possibly to other markup formats, which depends only
on the configuration).
Implemented in Java so it can be used in Linux, Windows, etc. More details on Sourceforge project's page.
httpserver - December 2006, simple UNIX HTTP server implementing HTTP 1.0 standard. Written in C and tested on Linux,
Solaris. More details.
Matfyzácké člověče nezlob se - August 2004, simple game written in Delphi using CLX library (compiled in Windows and Linux).
More details only in Czech.