FeatherPad

FeatherPad is a lightweight Qt plain-text editor for Linux. It is independent of any desktop environment and has:

Drag-and-drop support, including tab detachment and attachment;
X11 virtual desktop awareness (using tabs on current desktop but opening a new window on another);
An optionally permanent search-bar with a different search entry for each tab;
Instant highlighting of found matches when searching;
A docked window for text replacement;
Support for showing line numbers and jumping to a specific line;
Optional selection highlighting;
Automatic detection of text encoding as far as possible and optional saving with encoding;
Syntax highlighting for common programming languages;
Ability to open URLs with appropriate applications;
Session management;
Side-pane mode;
Auto-saving;
Spell checking with Hunspell;
Printing;
Text zooming;
Appropriate but non-interrupting prompts;
Haiku OS support (by khallebal at GitHub);
macOS support (by Pavel Shlyak); and
Other features that can be found in its settings, on its menus or when it is actually used.

Featherpad