Transferring to another non-profit

As some of you know, I sometimes suggest SPI as the next step on a
free and open source software project's growth from a group of
developers to an independent, autonomous, sustainable existance.

http://www.spi-inc.org/treasurer/associated-project-howto.html says "Your
Liaison may decide that your project is quitting SPI at any time. Any
assets and money held by SPI for your project may be transferred to the
501(c)3 US non-profit of your choice, or simply held until expended."

Is that a legal constraint in the US for 501(c)3 organisations?

What possibility there is for transferring assets to a non-US
organisation if a project wants to end its link with SPI?

Thanks,
--
MJ Ray (slef) LMS developer and webmaster at | software
www.software.coop http://mjr.towers.org.uk | .... co
IMO only: see http://mjr.towers.org.uk/email.html | .... op