Jagex decided to put the classic version of their long-running MMO, Old School RuneScape, on Gaben's platform which will probably result in an influx of players.
MMO fans and those looking for a nostalgia injection can download Old School RuneScape on Steam now and enjoy one of the most resilient games in the history of the industry.
Downloading OS RuneScape is free but the game does have the freemium business model and the monthly membership can be purchased in one, three, six or twelve-month increments. It costs less than World of Warcraft subscription but other than both games being MMOs, it's a bit hard to compare them properly.
Given the fact that RuneScape kicked off as a browser game initially, one would expect the system requirements to not be too high and one would be right in assuming that. Old School RuneScape Steam page lists extremely old components in both minimum and recommended specs, along with the modest 200 MB of disk space that is needed to store the MMO.
The fact that the devs listed Windows 95, 98, ME and XP as operating systems that may not allow you to run the game anymore testifies that the entry barrier on the hardware side is really low.
In other words, just run the game and go enjoy it like it's early 2000s again.