Patchamama is a binary patch maker/applier that works on directory tree. It can be used in application deployment, large scale project patching (including source and binary data). It use bsdiff for the binary diff job and 7zip for compression.
CalDAV sync for Android
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Stopped working on it. Doesn't make any sense to spend more time on it; I recommend e.g. DAVdroid as an opensource and ready-to-use solution on clientside.
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For code look at:
https://github.com/e7o-de/android.caldav