Altium2kicad can help you migrate an Altium project to KiCad, it
supports most features of .PcbDoc and .SchDoc, so it can convert both
the PCB and schematic. It consists of a few perl scripts that are
executed on the altium design files.
Donating to KiCad via The Linux Foundation is the preferred method of supporting
KiCad development. This support provides funds for project development and the
developers behind it. The Linux Foundation is a 501(c)(6) non-profit organization
in the US.