Release of Sigil 2.5.1: Enhanced Multi-platform ePub eBook Editor with Improved Performance and Bug Fixes

At the end of May 2025, the free and open-source multi-platform eBook editor [Sigil 2.5.1](https://sigil-ebook.com/) was released, utilizing Qt6 (and QtWebEngine). This project is designed for editing books in the ePub format, including both ePub 2 and ePub 3. The stable version Sigil 2.4.0 [was launched](https://habr.com/ru/news/873042/) in January 2025, while Sigil 2.5.0 was released in early May.

The source code for Sigil is written in C++ and Python and is [available](https://github.com/Sigil-Ebook/Sigil) on GitHub under the GNU General Public License v3.0. Build versions of the software [can be downloaded](https://sigil-ebook.com/sigil/download/) for Windows (Windows 10 (1809) and newer), macOS (macOS 11 Big Sur and newer), and Linux, including support for [Flatpak](https://flathub.org/apps/com.sigil_ebook.Sigil).

In Sigil version 2.5.1, previously identified bugs have been fixed, performance has been enhanced, and earlier introduced features have been refined.

Key updates in Sigil 2.5.1 include:

— Added an AppImage .desktop file with version information;
— Removed the bins element from AppImage where possible;
— Updated documentation, including version 15 of the Sigil_Plugin_Framework.