Mainframes are not open source friendly

IBM is a strange beast. On one hand, they gave away Eclipse and the Apache Software Foundation but on the other, they don't seem to embrace open initiatives when mainframes are involved.

You can read more about what happened to PSI and T3 Technologies on openmainframe.org. These examples are more on the hardware side but there is no sign of IBM opening up any of its z/OS software.

Most of the open source initiatives I have heard of such as http://www.opencobol.org/ or http://h3270.sourceforge.net/index.html are from third parties and do not attempt to run on z/OS itself.

I think that IBM's attitude toward open source on z/OS is harming the mainframe community and is counterproductive in the long term.