Early development

The new design was revealed to the public at E3 1999, where it earned several awards including Best Online Game and Best Action Game. By this time Team Fortress 2 had gained a new subtitle, Brotherhood of Arms, and the results of Walker and Cook working at Valve were becoming clear. Several new and at the time unprecedented technologies on show: Parametric animation seamlessly blended animations for smoother, more life-like movement, and Intel's multi-resolution mesh technology dynamically reduced the detail of on-screen elements as they became more distant to improve performance (a technique made obsolete by decreasing memory costs; today games use a technique known as level of detail, which uses more memory but less processing power). No release date was given at the exposition.

In mid–2000, Valve announced that development of Team Fortress 2 had been delayed for a second time. They attributed the delay to development switching to an in-house, proprietary engine that is today known as the Source engine. It was at around this time that all news ran dry and Team Fortress 2 entered six years of silent development. During that time, both Walker and Cook worked on various other Valve projects—Walker was project lead on Half-Life 2: Episode One and Cook became a Steam developer—raising doubts that Team Fortress 2 was really the active project that would be repeatedly described.