 Its author, Paul Le Roux, joined Shaun Hollingworth (the author of the Scramdisk) to produce the commercial encryption product DriveCrypt for the security company SecurStar.The popular source-available freeware program TrueCrypt was based on E4M's source code.However, TrueCrypt uses a different container format than E4M, which makes it impossible to use one of these programs to access an encrypted volume created by the other.