xtool is a command-line utility developed by the programmer (active in communities such as ZenHAX and CS.RIN.RU). Its primary function is to act as a precompressor – a tool that processes compressed data streams within proprietary installer setups (e.g., InnoSetup, InstallShield) to allow recompression with higher ratios or to enable modification of precompressed archives.
When raw data is passed to an archiver, it compresses much better than the pre-compressed data. When you eventually want to use the files, XTool re-compresses the data back to its original state during extraction. razor12911 xtool precompression tool