Linux /leenuhks/ or /linuks/, not /li:nuhks/ n.
The free Unix workalike created by Linus Torvalds and friends starting about 1991. The pronunciation /linuhks/ is preferred because the name `Linus has an /ee/ sound in Swedish (Linuss family is part of Finlands 6% ethnic-Swedish minority) and Linus considers English short /i/ to be closer to /ee/ than English long /i:/. This may be the most remarkable hacker project in history -- an entire clone of Unix for 386, 486 and Pentium micros, distributed for free with sources over the net (ports to Alpha and Sparc and many other machines are also in use).
Linux is what GNU aimed to be, and it relies on the GNU toolset. But the Free Software Foundation didnt produce the kernel to go with that toolset until 1999, which was too late. Other, similar efforts like FreeBSD and NetBSD have been technically successful but never caught fire the way Linux has; as this is written in 2001, Linux is seriously challenging Microsofts OS dominance. It has already captured 31% of the Internet-server market and 25% of general business servers.
Black shirt with the word linux written with a mirror image on the front and Tux the Linux mascot on the back. Tux logo by Larry Ewing.