Jay Hoffmann compiled a list of a fun list of browsers you’ve never heard of. The only one I did know was Camino:
After Netscape lost the browser wars and released their browser as open source, a few programmers began to work on a Mac version. They took the rendering engine from the in-progress browser that would eventually become Mozilla Firefox, and adapted it to the native Mac Cocoa API. The result was Chimera, later renamed to Camino, which had its first version in beta in 2002, a year before Safari — the first official browser from the Apple team — hit the market.