so many great actually-free choices. (not-free would include malware [all adware is malware], crippled freemium, nagware..)

It's sad that free must be qualified distinct from 'free'.

While maintaining various alternatives to this and that lists I could kick myself for not forging them all in one place thusly

http://alternativeto.net/software/hamachi/?license=free

I have had excellent success myself with remobo (tap/tun) and neorouter (mesh) and wippien (p2p). Each are cross-platform, but wippien has no OSX binaries.

Supplement lobby chat with xmpp texting and sip texting with optional video or calling

http://jitsi.org
http://jit.si
http://wiki.xmpp.org

http://remobo.com/
http://neorouter.com/
http://wippien.com/
http://no-www.org: if URLs fail for want of depricated zone feature (www dot) please poke them until they comply

HTH

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