ZIM (file format)
The ZIM file format is an open file format that stores wiki content for offline usage. Its primary focus is the contents of Wikipedia and other Wikimedia projects. The format allows for the compression of articles. ZIM file can also contain full-text search indices and other auxiliary files.
ZIM stands for "Zeno IMproved", as it replaces the earlier Zeno file format. Its file compression uses LZMA2, as implemented by the xz-utils library, and, more recently, Zstandard. The openZIM project is sponsored by Wikimedia CH, and supported by the Wikimedia Foundation.