Factor has always been developed by a relatively small team, which makes their achievements even more remarkable. The language's creator, Slava Pestov, was a very important driving force in its development until around 2011, when he stepped down from leading the project to focus on a new job at Google.
John Benediktsson has been leading the project since then, and as the post mentions, there are and have been many other contributors, but I think it's fair to say that the project lost a lot of momentum when Slava stepped down.
Joe Groff, who was another important early contributor, and who is now part of the Swift team at Apple, gave a talk that included an interesting critical retrospective on the factor project (or at least one chapter of it). I'm sure there was a better formatted version of it at some point, but this is all I could find:
John Benediktsson has been leading the project since then, and as the post mentions, there are and have been many other contributors, but I think it's fair to say that the project lost a lot of momentum when Slava stepped down.
Joe Groff, who was another important early contributor, and who is now part of the Swift team at Apple, gave a talk that included an interesting critical retrospective on the factor project (or at least one chapter of it). I'm sure there was a better formatted version of it at some point, but this is all I could find:
https://github.com/jckarter/zissou/blob/master/talk-notes.tx...
See "bad parts" for the criticisms.
Incidentally, these notes were the first place that I learned of the Julia language.