Aegisub - Aegisub is a free, cross-platform open source tool for creating and modifying subtitles. Aegisub makes it quick and easy to time subtitles to audio, and features many powerful tools for styling them, including a built-in real-time video preview.
Gaupol - Get Stuff Done.
Subtitle Editor - Subtitle Editor is a GTK+3 tool to edit subtitles for GNU/Linux/*BSD.
Gnome Subtitles - Gnome Subtitles is a subtitle editor for the GNOME desktop. It supports the most common
Jubler - Jubler is a tool to edit text-based subtitles.
Subtitle Workshop XE - Subtitle Workshop XE is the most complete, efficient and convenient freeware subtitle editing tool.