The VAR Guy rarely writes about executive changes at software companies. But in this case, he’ll make an exception. Former SuSE Linux CTO Jurgen Geck has joined Open-Xchange, the open source email provider, as CTO. Also, CXO Systems veteran Gerald Labie has joined Open-Xchange as CEO. The moves come at a critical time for Open-Xchange and the broader open source applications market.

In recent months, the open source industry’s collective focus has shifted from Linux and basic infrastructure software to full-blown open source applications. Red Hat recently announced plans to launch an online exchange that sells integrated open source applications from multiple partners. At the same time, MySQL is gearing up for a major customer conference later this month. The conference will showcase dozens of open source applications designed to run with the MySQL database.

Meanwhile, the open source email market continues to rapidly mature. In addition to Open-Xchange, early leaders include Zimbra–which has an installed base of about 6 million licensed users.