The market GitHub created was Social Coding and the idea that there were network effects to be gained by having all OSS in one place. This is the same thing that makes it difficult today for OSS projects to move off GitHub. If anything, GitHub deemphasized the "D" in DVCS.
My point, since you replied to my post, was simply that prior to GitHub, none of the other sites for OSS were trying to achieve the same goal. The goal was to establish a specific OSS community for a set of projects. SourceForge was a bit of an outlier in that a lot of projects used their distribution network, if they were not part of a foundation like Apache or Eclipse that had extensive mirrors setup.
SourceForge was never the main development and collaboration site for any of the major efforts happening around OSS.
My point, since you replied to my post, was simply that prior to GitHub, none of the other sites for OSS were trying to achieve the same goal. The goal was to establish a specific OSS community for a set of projects. SourceForge was a bit of an outlier in that a lot of projects used their distribution network, if they were not part of a foundation like Apache or Eclipse that had extensive mirrors setup.
SourceForge was never the main development and collaboration site for any of the major efforts happening around OSS.