The official website of Torsocks https://code.google.com/p/torsocks/ referred ‘Tor-Friendly’ and ‘Socks-Friendly’, what’s that mean? And how to sure an application is Socks-Friendly or not
I would assume the vague definition of, Socks-friendly is: able to be configured to use a SocksProxy without leaking DNS or circumventing the SocksProxy.
I would assume the vague definition of, Tor-friendly is: developed with Tor in mind. Socks-friendly; without leaking DNS or circumventing the SocksProxy and not being affected by protocol leaks (https://trac.torproject.org/projects/tor/wiki/doc/TorifyHOWTO#Protocolleaks). Eventually using Tor by default of having a wizard to offer using Tor.
The tor-talk mailing list might yield better results for this question.
For me a transparent proxy tool is to force any network connections of application into specific proxy, obviously Torsocks only can be transparent with friendly applications, that’s not any programs, I know Whonix can force any network traffic coming out from its Workstation, but is there any other less size proxy tool fully transparent?
Custom build minimal Whonix(-Gateway) (https://www.whonix.org/wiki/Dev/Build_Documentation) combined with Custom-Whonix-Workstation (https://www.whonix.org/wiki/Other_Operating_Systems) and eventually Physical Isolation (https://www.whonix.org/wiki/Physical_Isolation).
Non-Whonix Custom build Transparent Proxy:
Firewall rules, Local Redirection Through Tor (not as secure from clearnet leaks as Whonix) (https://trac.torproject.org/projects/tor/wiki/doc/TransparentProxy)