Proxy support only for Windows?

I read that sparkle is crossplatform.

Does it also support proxies for mac target or only windows target?
I am currently using indy, where I have lots of connections running in threads, each use another proxy. Can I do the same with sparkle?

You manually use different proxies in each connection in each thread?

Yes, each thread use another proxy

Please contact us directly via e-mail so we can discuss better about this, including exchanging some source code.