Are there any success stories of coop startups in technology (namely software)? I don't mean like a coop store where customers are (or can be) members, but worker cooperative one where membership is exclusive to (in this case) developers and IT people, and each can only have one "share".
If assume that you are asking this so that you can assess whether or not it's a good idea. If that is the case, then an answer to your question isn't going to give you that information.
Even if there are hundreds of success stories, that doesn't help you unless you know how many tried and failed in the first place. Just like lots of failures don't mean it's generally a bad idea unless you know how many succeeded.
E.g. If there are 100 failures, but there were 10,000 companies that tried it, then trying a coop isn't a bad idea. But if there are 100 failures and 110 companies tried it, then it's probably not a good idea.
All that said, the dynamics of a startup aren't something that can be so easily put down to a structure. It's about a whole lot of other aspects which can't really be measured (like passion, commitment, or luck).