[GitHub] Unreal Engine 4 Source

Isn't Unreal Engine 4 open source?

Yes; however, the source code is currently locked behind a private repository that's accessible by being in the EpicGames group on GitHub.

Won't this be out of date by next week?

If I didn't keep this up-to-date, then of course this will become outdated rather quickly. I do plan on writing a program that takes the effort of creating smaller patch files from the difference between two files and I'll share the source of that program to this community in a thread when I finish developing and testing it.

Why is the archive size so small?

Mainly because of compression and because the source code of a program tends to be much smaller than the file size of a compiled program. This is mainly determined by the compiler and the compiler settings used to create the program.

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