Bitstream's Courier 10 Pitch v. 2.0 was donated to the X Consortium under the MIT license in 1990. The license permits modifying and distributing the font. Courier Code is Bitstream's Courier 10 Pitch with two minor modification. The lowercase "L" has been altered to distinguish it more clearly from the number one. The zero has been modified to more clearly distinguish it from the uppercase "O". These changes make it more suitable for use in programming.