So.cl was a social networking service and social search engine operated by Microsoft FUSE Labs. They announced on March 7, 2017 that it would be closing down So.cl on March 15, 2017. so.cl also is the name of the social media section on the sizeof.cat site.
Github Enterprise source code
, leaked on November 05, 2020; it seems Microsoft is really trying to get it removed. Not mine, I just ran across the zip archive. 😉