New version for SeaMonkey on addons.thunderbird.net!
Full list of changes since 1.1:

v2.7.1 - Released December 7, 2020
*Minor code cleanup to hide a console warning.
Previous Versions

v2.7 - Released November 20, 2020
*Fixed sending of quick reply Forum Post Style.
*Fixed selection of dark mode Forum Post Style.
*Minor code cleanup.

v2.6 - Released September 20, 2020
+Added difference between topics and posts in format application checkboxes.
+Added "Sprinkles" and "Paw" post styles.
+Inserted "Post Style" DIV in dark mode.
*Improved "Already Formatted" detection.
*Improved special formatting tag collision detection.
*Fixed overzealous lookahead for special formatting.
*Moderate code cleanup.

v2.5 - Released August 28, 2018
+Added Ukrainian localization.
*Improved namespacing to prevent issues with ES6.

v2.4 - Released August 16, 2018
*Support Pale Moon 28.

v2.3 - Released April 5, 2018
*Fixed Quick Reply style selection positioning.

v2.2 - Released March 27, 2018
*Corrected icon paradigm.

v2.1 - Released February 24, 2018
+Added support for new post styles.
*Fixed Options button on web pages.

v1.2 - Released October 25, 2017
#Changed update system to use my own website instead of relying on AMO.
*Fixed compatibility with HTTPS version of website.
#Allowed extra formatting in Private Messages.

Fixed some Options window functionality issues with older versions of Firefox.
Fixed an issue with Firefox 44 and above due to the variable scope js change.

Fixed bug when removing a Formatting Profile.
Fixed bug that prevented Extra Formatting entry fields from being disabled when no Extra Formatting Profile is selected.

Added PaleMoon target application entry.
Added Public Domain notice to source files.
Upped version compatibility numbers.

+Added multiple Format profile system. The Disable Formatting checkbox has been replaced with a dropdown list of formats.
+Added Options button to change GaiaFormat settings.

+Added some missing locale data.
+Added Swedish locales.

#Changed all settings to be part of the extensions group.
+Added synchronization of settings through Firefox Sync.

*Fixed regression with formatting within tags.
+Added notification about issues with square bracket usage.

Just a version compatibility update.

#Consolidated Firefox 1.5 and 2.0+ versions.
+Added default Forum Post Style application to Quick Replies.

*Fixed URI encoding error, which caused percent signs (and possibly other characters) to break formatting.
-Removed temporary error handler dialog.
*Fixed Mac issues by converting options dialog into a normal window.

*Rewrote parsing system to handle quote blocks correctly.
+Added locales for Turkish. Thank you BabelZilla.org.

+Added Import/Export feature.
+Added Dutch, Portugese (Brazillian), and Chinese (Simplified) locales.
+Added support for new Quick Reply feature.