I wrote a billing system for a company written in VB6 and MS Access! 😀

It's been running for 9years now.

I wrote some parts of a library system - mostly Java Swing desktop applications and a web application for catalog search - which is still in production in big Hungarian libraries (like FSZEK: saman.fszek.hu).

I also have a lot of code in a big logistics system written for a big cement company.

news.com.au's markup is still based on HTML patterns I wrote c2008. At one time the entire news ltd metro stable ran on that markup standard (precursor to what I'd now call a UI library). Lots of details have changed but the core page sections, group/item/block, etc are unchanged. It's pretty cool to see that a site built to support IE6 with float layouts is still using the same HTML, but now running CSS Grid.

Griffith University's phone book pages still use the vcard microformat HTML I cooked up with a coworker c2006. The design is still basically the same too (barring a broken image ;)), I made the listing look the standard business cards at the time.

The very oldest code would be web pages I built back in 1996 - since they are flat/static files they still work. That's a testament to the web being backwards compatible and not a testament to my code ;)

I've been working on the same codebase for 10 years. Much of it has been replaced over time but some of the stuff I wrote 9 years ago is still running.

I made a website to schedule work hours at a student job, which I recently found out is still running today.

I unfortunately lost the code for the game that was my high school final project... Plus most of the code from my teenage years... I didn't use VCS back then (Github didn't exist).

You have me curious now :) Back in 2002, I worked on a bunch of internal apps for a company, and I know they were using them still up to a few years ago.

If they (rightfully) shut those down, then I know I still have code running on NotebookReview.com and their associated web sites.

I am not quite sure but some parts of emarsys.com and the-impossible-project.com could be still running ;D the last time I heard was over 1 year ago so who knows ;D ....

For me, it's Hashnode's codebase. It's my only project which running in production for this long. 😀