The IDX Client and Server builds are to help with final pre-deployment testing. They will be distributed to TAP and OEM customers via Connect, similar to the bi-weekly RRP audience. Timebomb behavior identical to RC. Limited servicing. Will reuse RC EULA. Same languages as RC Exit (EN,DE,ES,FR,JA)."
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"This milestone is termed the "Internal Developer Client and Server" (IDX) build - it'san internal quality term we use meaning that the build is stable enough to deploy and evaluate, but may contain more minor bugs than a RC build."