One of the most interesting features of OmniROM is OpenDelta. This innovative OTA system created by XDA Senior Recognized Developer Chainfire uses open delta technology to bring updates in an easy, bandwidth-friendly way. In short, OpenDelta downloads only files that were updated since the last downloaded nightly.

If you thought that OpenDelta was a feature only available in OmniROM, you were right. But it's an open-source project, so porting it to work with other ROMs is absolutely possible. If you ever wondered how to add it to your ROM, XDA Senior Member werty100 made a pictorial guide with a complete explanation of OpenDelta usage. With werty100's guide you will learn how to set up Eclipse to compile an OpenDelta APK and even more important, which values should be changed to work with other ROMs with nightlies.

To fully incorporate the incremental OTA system into any ROM, only two files require some XML changes. And since it's not as difficult as Java or Smali, almost everyone should be able to add it to their ROM.

If you are keen to learn more about making OpenDelta work on almost every ROM, head over to the original thread to find all the relevant information.