WELSIM 2026R2 releases with all new dark theme GUI

SimLet

April 1, 2026

WELSIM, a general-purpose engineering simulation and analysis software, has released its latest 2026R2 version (internal version 3.3). Compared to the previous release, version 2026R2 introduces a majorly upgraded underlying framework alongside a new dark theme, improving the graphical user interface.

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All new dark theme

The newly added dark theme reflects current desktop application designs and is gentler on the eyes. Users can set the appearance theme in Preferences and have three options available: Classic, Dark, and Light.

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The Classic theme is similar to the Light theme, whereas the Dark theme features a dark background with light‑colored text and icons in the foreground. Starting with this version 2026R2, WELSIM’s default style will be the Dark theme.

Comprehensive Framework Upgrade

The new version upgrades the key foundational framework, including updating the GUI framework Qt from 5.15 to 6.10 and the 3D rendering engine VTK from 8.2 to 9.2.

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Upgrading both core frameworks across major versions has improved WELSIM’s stability and performance.

Other Improvements and Upgrades

The new release optimizes and advances existing features and adds more automated test cases, delivering a better user experience in WELSIM.


Disclaimer: WelSim and its developers are not affiliated with Qt or VTK, nor are they associated with the above‑mentioned development teams or organizations. References to Qt and VTK are made solely for reference in technical blog posts and software documentation.