New features
Full text search: Add a button to re-index a book, useful if the book's contents have been changed outside calibre
Search queries now support quoting using "docstrings" for easier escaping
Linux installer: Check for libEGL as the QtGui module in Qt 6 links against it and many Linux servers dont have it installed
Bug fixes
macOS: Blacklist older versions of the DeDRM plugin as they caused crashes and failures to add books.
Fix a regression in 6.0 that caused crashes in the Manage authors dialog
Closes tickets: 1981453
Fix a regression in 6.0 that broke touch screen interaction
Fix a regression in 6.0 that caused a few checkboxes to stop working
Closes tickets: 1981627
Linux: Fix a regression in 6.0 that broke handling of mouse clicks on some Wayland systems with a touchpad
Closes tickets: 1981629
ToC Editor: Fix a regression in 6.0 that broke styling/images in the preview panel
Windows: Fix window titlebars not dark in dark mode
Full text search: Show a warning when indexing/searching a library on an FAT drive
News download: Do not add aborted/failed article titles to the comments metadata
Full text search: Fix books edited with the Edit book tool not being automatically re-indexed
HTML Input: Fix handling of deeply nested files on Windows
Closes tickets: 1981438
Fix a regression preventing using a non-integer value for the tweak to change book details font size
Closes tickets: 1981188
Fix moving library not moving the full text search index
Fix some custom icons in the calibre config directory not overriding the theme/builtin icons
Linux installer: Fix glibc version check also being done when installing older versions
Windows installer: Refuse to install on Windows 8 as thanks to Qt 6 calibre 6 does not work on Windows 8
Update the BigBookSearch metadata plugin for website changes
Improved news sources
The Economic Times India
https://calibre-ebook.com