From IBM:
IBM programmers yesterday made what they believe is the first
ever submission of 64-bit code to the Open Source Community. It
will be up to the community to decide whether the code is
acceptable for integration into the Linux code tree for the widely
anticipated 2.4 Linux kernel. The code will enable a 64-bit driver
for the IBM eServer z900, the reinvented mainframe. The submission
comes several months earlier than expected and ahead of the 64-bit
Intel driver code, which many believed would be the initial 64-bit
Linux code.
An experimental version of the code is available for downloading
at IBM’s developerWorks website:
http://oss.software.ibm.com/developerworks/opensource/linux390/whatsnew.html.