A retirement gift for an engineer
A retirement gift for an engineer should be as old as the career, or exactly the work the career was. The catalog has both, drawn as bars on a mug.
Match the decade they entered
A retirement gift for a programmer fails when it looks like a gift for someone who started last year. Match the piece to the era they walked in, or to the system they refused to let die.
TeX if the career was papers, books, or any shop that still trusts Donald Knuth's program to set type. The bars are main_control, the procedure that decides what TeX does next. A lawyer cleared the listing. The name TeX stays his. CERN web server if they were online early enough to remember the web as a server you were asked not to switch off. CERN put that software in the public domain on 30 April 1993. Linux start_kernel or Git if they built the later stack and stayed for the maintenance. A retirement gift for a software developer who spent twenty years in that stack does not need a newer logo. It needs the boot, or the first commit.
Apollo 11 ignition if the career was control systems, aerospace, or simply a love of machines that had to be right. Don Eyles and Peter Adler, 1969, routine BURN_BABY_BURN. The name came from a radio shout by Magnificent Montague, as Eyles told it. Public domain. The picture is tall because the tables are tall. That is a fair portrait of a long job.
A mug on the shelf at home
Retirement moves the desk into a house. Ceramic belongs there. The white tee is the same picture if they have always worn the work on a shirt, and you know that because you have seen it. For everyone else, buy the mug. Redbubble prints and ships to the EU and the US.
One piece is enough. A set looks like a catalog. A single routine looks like you were paying attention.
If the team is buying together, choose the piece in one conversation. Three people with three tabs will produce three mugs and a story about how hard it was to agree. The speech at dinner can be long. The object should still be one routine, old enough that a person who was not in the room can see why it was the one.
Keep the credit as long as the career
Long careers collect wrong stories. This catalog is strict about them. Greg Walsh wrote the Quake inverse square root, not John Carmack, if that piece comes up in the toast. Aaron Swartz was one author of RSS 1.0, at 14, with the RSS-DEV group, not the inventor of RSS alone. The Hello, world bars are Brian Kernighan's program, not a page from the 1978 book.
You do not need to recite the license at dinner. You do need the mug to point at a page that has the notice, for the GPL pieces, and the true names, for all of them. Which piece to give walks the traps if you are still choosing on the morning of the party.