To the editors:

In your article on the MyDoom Virus (News, “MyDoom Virus Infects Harvard,” Feb. 4) You called open source software ‘uncopyrighted’ software. This is incorrect. Most open-source software is covered by the GPL or the BSD license (or similar licenses such as Apache and PHP license). If a programmer contributes to Linux she does not revoke her copyright on the code. She simply gives the user a license to use that code and to copy and modify it as she wishes. The copyright holder can still release the same code (hers) under a different license-for example, the MYSQL database is released under both the GPL and a commercial license.

Without copyrights the GPL would not work because any company could hijack the code (like Microsoft), extend it with proprietary code and release it as a binary only without giving others the opportunity to change the code. Eventually such a fork might discourage open source developers to write new code and the code would no longer be freely available after a short while.

Markus Mobius

Feb. 4, 2004

The writer is assitant professor of Economics.