Along those lines, Britain joined the EU a year after Smalltalk-72 and K&R C were introduced. Smalltalk inspired Objective-C, which is still used today in Macs.
The British Constitution can be seen as a large piece of legacy code which has never been tossed and rewritten from scratch, just incrementally patched and refactored over a really long period of time.
Downside: lots of bizarre complexities, bits of dead code, stuff that works as long as nobody touches it etc. Upsides: it's really stable.