Berkeley sees machinima as "a strangely hybrid form, looking forwards and backwards, cutting edge and conservative at the same time". Machinima is a digital medium based on 3-D computer games, but most works have a linear narrative structure. Some, such as "Red vs. Blue" and "The Strangerhood", follow narrative conventions of television situational comedy. Although other virtual theatrical performances have taken place in chat rooms and multi-user dungeons, machinima adds "cinematic camera work". Previously, such virtual cinematic performances with live audience interaction were confined to research labs which had powerful computers. 