One of the legacies of bringing IG to FB was ReactJS. Prior to the IG acquisition ReactJS was used internally across product surfaces inside the FB apps… but w

One of the legacies of bringing IG to FB was ReactJS. Prior to the IG acquisition ReactJS was used internally across product surfaces inside the FB apps… but was not an open source library. IG was acquired as a mobile app but did not ship a first-class WWW product for browsing posts and profiles. I believe it might have been Pete Hunt that wanted to build the IG WWW product surface on ReactJS. This meant decoupling ReactJS from hardcoded dependencies and assumptions that were specific to the FB products. Once ReactJS was decoupled from those FB specific details it was ready to ship as a legit standalone infra in 2013. Would ReactJS have shipped as standalone infra without IG? Maybe… eventually. The FB philosophy in those days was generally not to build infra just for the sake of building infra. Infra was supposed to solve for real-world problems and measurable product impact. If the only front-end products inside FB were on FB and there was no impact to be earned from decoupling those dependencies… it's possible that engineers might not have been incentivized to ship it open source as soon as they did.