Index of cache files created by Runescape, an online multiplayer game; stores data about cache files (e.g. .IDX255 and other files) saved by Runescape; index files are typically named "main_file_cache.idx0" and should not be opened manually.
Program(s) that open idx0 files
Windows: Jagex Runescape
Information from FileInfo.com - The File Extensions Resource.
http://www.fileinfo.com/extension/idx0
