I started work in 1998, first thing I worked on was part of the Bank of England regulatory reporting software used by 100s of banks. I'm pretty sure some of that will still be in use.<p>The next thing I worked on was for British Gas for one of their core processes. I changed at least 100 screens and rewrote their daily batch process. I just heard that's still going and unlikely to have changed.<p>Both systems originated from early 1990s
Our company has COBOL that's from the 80's. There's some Java batch stuff and Oracle SPs that I worked on 7-8 years ago that are still in use.