A recent post (https://news.ycombinator.com/item?id=6606056) about using a 6 year old laptop as the developement machine.
I have just retired an old Compaq with an Intel Celeron running WindowsXP with 4Gb of RAM just last year, it was a couple of years after Compaq was acquired by HP. I bought the Compaq computer is 2004. It lasted 8 years before it died. My development setup was through a terminal session and editing code with Vim.
So I am asking how old is your regular computer and what is that computer and its configuration
It will be interesting to see what is the oldest machine and its configuration.
Edit: corrected the typo with the Memory config.
If by "use regularly" you mean utilize for direct user interaction with the machine, then that would be a Compaq laptop from 2006 with 768M of RAM and an AMD Sempron CPU.
If by "use regularly" mean "use to perform a task" then that would be a Supermicro dual Pentium-2 400Mhz system with 512M that acts as a PVR scheduler/recording driver. I've long since lost track of exactly when that motherboard was purchased, but it was somewhere in the 1998-2002 time frame. That puts it at somewhere between 11 and 15 years.
If you'd asked this question last year I could have answered an old PentiumPro box (with something like 128Meg or 256Meg of RAM) that a buddy from work gave me that was acting as an internet firewall. It likely hailed from the 1995-1996 time frame. But I retired it last year in favor of an old Pentium4 Thinkstation that I got from a local store in their "refurb" section. I have no idea of what year the Thinkstation hails from.