Usage: Edit the file erjang_cfg.properties `erjang.otp.root` and make it point to an R13-based release before running `ant jar otpjar`. Remember, Erjang does not work with R14-based releases yet, because the file driver changed API and we've not updated that. The current code in ClassPathResource.java is ugly and slow: implementation of `file:list_dir/1` iterate through the entire classpath. ... and `file:file_info/1` opens the .jar every time it is called. Should maybe cache some directory-like structure, but those are really only called during boot so be careful to cache for too long.