Windows 10 has reached RTM on Build 10240.16384, but work has not stopped there, and actually is still on full pace. A check in BuildFeed will show that development is now proceeding in 3 different channels. 1. Builds were compiled starting with 10500 in TH2, it's the RedStone builds, targeted for next Fall. The latest build known to-date is 10504. 2. Builds are still compiled with the main build no. 10240, these are the ZDP(Zero Day Patch) builds, latest known is 10240.16389. They were intended to be added to the GA build to be released on Jul 29, probably build 10240.164xx. GabAul had used a number of times the term "Final Release" for the Jul 29 GA release, we don't know how MS would name it officially, also, as Insiders could install 10240.16384 as of now, we don't know 10240.164xx would come as a patch, or as a full ESD update. 3. The 3rd channel are the builds after 10240, the latest known is 10242, these are the GDR1 builds targeted for release in this Fall, in fact, GDR1 had been started in the ur1 branch quite some time ago, and the builds 10192, 10208, 10224 and 10240 were GDR1 builds, with the exception of the TH1 branch builds which were TH1 RTM sign-off candidates(which explained the need to jump in 16 numbers). As TH1 has hit RTM, there is no further need for the 16 multiple rule, so build nos started with 10241 afterwards. It would be interesting to see how MS would handle GDR1, it could be done either: - Previously GDR's would take the RTM no. and increased the delta, but the delta of 10240 are now used for the ZDP builds, so after Jul 29, win10 GDR1 might still go this way and further developed as 10240 with increased delta. ..Or ... - There is no rule that it has to go like above, so GDR1 could still be compiled with increased build numbers, and chances are we could see the rumored build 10400, and MS could even name it something else, like win10.1, or whatever.