Source of IBM-approved PowerPC distribution: https://www.yellowdoglinux.com/
https://lists.yellowdoglinux.com/
Support source for Linux on IBM-supported PowerPC platforms: https://www.linuxcare.com/
IBM Linux web pages:
https://www.ibm.com/linux/
https://www-4.ibm.com/software/is/mp/linux/ https://www.rs6000.ibm.com/linux/
Sources for Linux on IBM Intel-based platforms: https://www.calderasystems.com/
https://www.turbolinux.com/
https://www.redhat.com/
https://www.suse.com/
https://www.keylabs.com/
Other sites of interest:
https://list.linuxPPC.org/
https://www.linux-business.com/
https://www.linuxjournal.com/
IBM Hardware web sites:
https://www.us.pc.ibm.com/ (use 6070 as search term) https://www-4.ibm.com/software/year2000/papers/aixy2k.html (Y2K firmware status information)
https://servicepac.mainz.ibm.com/ (Site of Electronic Pocket Reference Manual) https://www.rs6000.ibm.com/