Comment by djwatson24

After thrift became an Apache project, internal Facebook employees found it harder to iterate using external tools than our internal github repos. Many of the changes depended on things that weren’t open source, or only recently became open source in folly. We do hope to merge as many changes as possible back upstream, but felt it was more important to get the code open source as quickly as possible. In addition, fbthrift is a dependency for several other projects Facebook wants to open source in the near future.