Kaa-ching is nowadays on various forums and irc the alias for Klaas van Gend.
Origin of nickname
Klaas originally always used kvangend as login - until he realized that 'vangend' means catching in his native language, Dutch.
For about a day, he changed his nickname to kcatching, and then switched over to kaa-ching. It looks better and also had some bearing on his job (At the time, he worked in the sales organization of MontaVista).
Several people already confused his new nickname to be Chinese, which of course adds to the fun.
Klaas nowadays works for Vector Fabrics, a small company based in Eindhoven, The Netherlands that works on a tool to help parallelization of sequential C or C++ code.
Focus in this wiki
Back in 2008-2009, Klaas has been spending most of his time in this wiki on the various books in the Category:Books category.
Klaas was the lead developer for the open source user land project to bring support for UMTS to Linux: umtsmon. If time permits, he still programs on his other open source project The Butterfly Effect, a physics computer game about cause and effect, not entirely unlike the famous "The Incredible Machine".
Klaas was a board member of the NLUUG and is one of the co-organizers of the Embedded Linux Conference Europe, nowadays merged with LinuxCon Europe.
He is famous for doing the end game.