alternatives ? (link) is dead (shot by the Sheriff, but he didn’t shoot no deputy, ooh, ooh,..) and by April 30th you better backup your belongings, otherwise they go /dev/null. (The domain will be removed as well). Unfortunately it was well integrated with Netbeans and this level of collaboration you wouldn’t achieve with another OS code repositories. No choice, so here a comparison of services on wikipedia (link).
My personal choice: I will select one with a public API, potentially could create a plugin (if it is not available yet). Maybe Launchpad or Github.