Subtitle Edit - Free subtitle editor with visual sync, time adjustments etc.Subtitle Edit Online · Subtitle Edit Videos · Subtitle Edit 3.
Crowdin - Localize your product in a seamless way
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.
POEditor - The translation and localization management platform that's easy to use *and* affordable!
Subtitle Editor - Subtitle Editor is a GTK+3 tool to edit subtitles for GNU/Linux/*BSD.
Lokalise - Localization tool for software developers. Web-based collaborative multi-platform editor, API/CLI, numerous plugins, iOS and Android SDK.