ALL the programs listed on this forum are Gnutella network (G1) programs. LimeWire did introduce torrent downloading option a handful of years ago, but that's not its main feature.

When I saw you title the thread multi-platform I thought you meant as in Linux, Mac & Windows, etc.
However, you meant multi P2P networks. I'm not the best to answer this question but there are a few other programs which do download from multiple networks or/& torrents. Basically G1, G2 & possibly torrents. G1 is the regular gnutella network.

Several of the GnucDNA Based Gnutella Clients will also utilize the G2 network.

As for torrents, I'd personally recommend a separate specialised torrent program such as Vuse or uTorrent. These torrent programs are accepted at all torrent sites including private torrent sites, whereas the part-timer torrent programs are usually not allowed access at the private torrent sites. If you only seek public torrents then the part-timer torrent programs can be used in most cases.

BTW as for ShareAza, there are two versions. The company was taken over (hijacked) by a company group related to the RIAA a year or two ago. However, the original developers continued development on the original program at SourceForge.net. More explained here http://www.gnutellaforums.com/sharea...-com-fake.html