I've still got my 701 4G (it was my daily driver from 2008 to 2016) - I've had to replace the keyboard and power supply and upped the RAM to 1Gb. It runs Haiku OS currently (really well, despite the screen resolution being "officially" below requirements). It'll also run antiX, Q4OS Trinity, Refracta, Void, Alpine and FreeBSD reasonably well.