TCX is a system designed for the transparent decompression, execution and recompression of executables under Unix. It allows configuration options such as the type of compression system used (compress(1), gzip(1), your own local system etc), timeouts between recompressions, and emergency directories in case a decompression fails from shortage of disk space. The system is designed with a reasonable amount of robustness in mind, such as in the event of system crashes, or races on trying to uncompress, compress or execute something.