Free Software

I've contributed to the following products/projects to a greater or lesser extent:
QuickFIX is a library providing a Financial Information eXchange (FIX) engine for connecting to markets such as NYSE, Euronext and others. In the course of my work at Anvil I provided a number of feature enhancements to version 1.5 which was released in May 2003.
Automake is a software build tool. I contributed functionality useful for parallel builds of projects using CORBA IDL and other "Built Sources".
TAO is the "The ACE ORB", an open source CORBA request broker with good standards compliance and performance.
unixODBC provides database connectivity on UNIX platforms. I contributed portability fixes for HP-UX and Sun Solaris.
A free C++ version of JDBC v2 over ODBC. This is much easier to use than the ODBC C API. I contributed fixes to storage of binary large objects and managed the 0.2.3 release.
A fine perl CORBA binding. I provided the test suite and some bug fixes.
Other projects I use and follow, but haven't submitted code to include:
Lots of Java items since I wrote this page...  Eclipse,  Scala

The GNU Compiler Collection
An excellent C and C++ compiler, I'm interested in the C++ implementation from the point of view of features, portabilty and compile time speed.
JBoss is a excellent free Java J2EE application server. Don't spend any money on websphere before you've give JBoss a try.
Libtool is an very useful tool to portably build shared libraries.

Plus many more...

Alex Hornby