Homepage: http://www.nikse.dk/SubtitleEdit/Subtitle Edit
Subtitle Edit is a free (open source) editor for video subtitles - a subtitle editor
With SE you can easily adjust a subtitle if it is out of sync with the video in several different ways.
You can also use SE for making new subtitles from scratch (do use the time-line/waveform/spectrogram) or translating subtitles.
For a list of features see below or check out the Subtitle Edit Help page.
On my blog you can download latest beta version and read about/discuss new features.
Also, you can watch a few videos about installing and using Subtitle Edit.
Dny238 has written a nice tutorial about Syncing Subtitles with Subtitle Edit
A Subtitle Edit dll (Subtitle Edit Light Library) is available for programmers (LGPL licence). Initially created and used by Sublight (a free Windows application for searching and downloading movie subtitles).
Download latest version of Subtitle Edit
For Windows XP users: SE requires Microsoft .NET Framework Version 2.0 or newer.
Get the full C# source code - GPL or LGPL license
Blu-ray sup reading code is under the Apache License and Matroska subtitle parsing uses zlib code with a BDS style license.
Create/adjust/sync/translate subtitle lines
Convert between SubRib, MicroDVD, Advanced Sub Station Alpha, Sub Station Alpha, D-Cinema, SAMI, youtube sbv, and many more (100+ different formats!)
Cool audio visualizer control - can display wave form and/or spectrogram
Video player uses DirectShow, VLC media player, or MPlayer
Visually sync/adjust a subtitle (start/end position and speed)
Auto Translation via Google translate
Rip subtitles from a (decrypted) dvd
Import and OCR VobSub sub/idx binary subtitles (can use Tesseract)
Import and OCR Blu-ray .sup files (can use Tesseract - bd sup reading is based on Java code from BDSup2Sub by 0xdeadbeef)
Can open subtitles embedded inside matroska files
Can open subtitles (text, closed captions, vobsub) embedded inside mp4/mv4 files
Can open/OCR XSub subtitles embedded inside divx/avi files
Can read and write both UTF-8 and other unicode files and ANSI (support for all languages/encodings on the pc!)
Sync: Show texts earlier/later + point synchronization + synchronization via other subtitle
Adjust display time
Fix common errors wizard
Spell checking via Open Office dictionaries/NHunspell (many dictionaries available)
Remove text for hear impaired (HI)
Swedish to Danish translation built-in (via Multi Translator Online)
Effects: Typewriter and karaoke
History/undo manager (Undo=Ctrl+z, Redo=Ctrl+y)
Multiple search and replace
Change casing using names dictionary
Merge short lines/split long lines
Export to PNG images (+bdn xml), Adobe Encore FAB image script, VobSub, Blu-ray sup, EBU stl, PAC, and plain text
Download Page: http://code.google.com/p/subtitleedit/downloads/list
Download zip archive and extract. Writes settings in application folder. Required .NET 2.0.