Fork of KDE 3.5 created by users who rejected KDE 4's radical redesign, continuing the classic desktop experience for over 15 years.
TDE is a full desktop environment forked from KDE 3.5, ported to use TQt (a compatibility layer over Qt 4/5) instead of Qt 3. It includes a window manager (TWin), file manager (Konqueror), panel, control center, and hundreds of applications. All KDE 3 'k' prefixes were renamed to 't' prefixes.
When KDE 4.0 launched in January 2008, it was a disaster. The release was buggy, incomplete, and represented a radical departure from the polished KDE 3.5 desktop that millions of users loved. KDE developers had rewritten virtually everything from scratch using Qt 4, introducing the Plasma desktop shell, a new file manager (Dolphin replacing Konqueror), and entirely new paradigms for desktop interaction. Many users and distributions were furious.
Timothy Pearson, who had been coordinating Kubuntu remixes that kept KDE 3.5 alive after Kubuntu switched to KDE 4, decided to formalize the effort. In 2010, he launched the Trinity Desktop Environment (TDE) — named because 'Trinity' means 'three,' a nod to its KDE 3 heritage. The first release, TDE 3.5.11, arrived on April 29, 2010.
What started as a preservation effort evolved into genuine independent development. The Trinity team ported the entire desktop from Qt 3 to a custom fork called TQt (Trinity Qt), allowing it to run on modern systems while maintaining the classic look and feel. They renamed all binaries from 'k' prefixes to 't' prefixes to avoid conflicts with KDE installations and built their own build system.
The project survived through sheer determination. When Timothy Pearson stepped back, Slávek Banko took over leadership. The R14.1.5 release in November 2025 added tiling functionality to the TWin window manager for multi-monitor setups — a thoroughly modern feature grafted onto a classic foundation. TDE packages are available for Debian, Fedora, Arch, openSUSE, and many other distributions.
Trinity is packaged by distributions like Q4OS, which provides a polished KDE 3-style experience that runs well on older hardware. It remains the only maintained fork of KDE 3.5, serving users who never accepted that the KDE 4 redesign was an improvement.
KDE 4.0 releases to widespread criticism for instability and radical redesign
Trinity Desktop Environment 3.5.11 released as a formal KDE 3.5 fork
TDE R14.0.0 released, completing the port from Qt3 to TQt
TDE R14.1.5 released with tiling window management support
Trinity proved that a small team can maintain a full desktop environment for over 15 years through pure community dedication. While it never achieved mainstream adoption, it preserved a beloved desktop paradigm and provided a lifeline for users on older hardware. The project influenced the broader Linux desktop conversation about respecting user preferences during major redesigns.