Digital Foundry takes a look at both versions of the original Deus Ex, the PC & PS2 releases. Both have a lot of advanced technology and hearing about the mostly ignored PS2 port for the first time is great. Digital Foundry explains a lot, like how the team behind the project had experience with First Person titles in the past and how using Unreal Engine for the title allowed for complex tools to build the games stealth mechanics.
Its a great video and something to watch if you enjoy recent Deus Ex games; always good to look-back at what started a series after all.