A few weeks ago I mentioned the amount of merger and acquisition activity in the open source sector in recent years and that it might worth trying to build a table of open source M&A deals.

As it happened Raven was thinking along the same lines and by delving into the CAOS Theory archives and The 451 M&A KnowledgeBase (subscribers only) that’s precisely what we’ve done.

One trend that emerged very quickly is how much of a driving force Red Hat has been in terms of acquiring both open source and proprietary vendors.

There have been 72 mergers and acquisitions involving an open source software acquirer or target (or both) according to our figures.

Red Hat has been involved with 16 of them, spending the best part of $1.3bn (and that’s just the disclosed amount).

Some, such as the JBoss acquisition, are well known. Others, such as Hell’s Kitchen Systems, will test the memory.

Here’s the list in full

• 1999 Atomic Vision undisclosed
• 1999 Cygnus Solutions $674m
• 2000 BlueCurve $33.9m
• 2000 C2Net Software $42.7m
• 2000 Hell’s Kitchen Systems $85m
• 2000 Wirespeed Commnuications $30.5m
• 2001 Akopia undisclosed
• 2001 Planning Technologies $47m
• 2002 ArsDigita undisclosed
• 2002 NOCpulse undisclosed
• 2003 Sistina $31m
• 2004 Netscape Enterprise Solutions (AOL) undisclosed
• 2006 JBoss $350m
• 2007 Exadel (Tools Product Line) undisclosed
• 2007 MetaMatrix undisclosed
• 2007 Mobicents undisclosed

What’s particularly interesting about this list of targets is how many of them leave you reaching for the ‘where are they now?’ file, including some that it paid a very high amount for (although you can put a lot of the valuations down to the dot com boom).