Aegisub

Aegisub is an open‑source subtitle editor that provides tools for timing, styling and typesetting subtitles for video files. It supports visual waveform and spectrogram displays, allowing precise alignment of subtitle cues with audio, and offers a rich set of styling options such as font selection, colors, positioning and karaoke effects. The editor includes scripting support for automation and can handle multiple subtitle formats.

The software is aimed at hobbyists, translators, fansubbers and professional subtitlers who need fine‑grained control over subtitle appearance and synchronization. Its cross‑platform nature lets users on Windows and macOS build and run the application from source, with dependencies managed through Visual Studio, DirectX SDK, wxWidgets and other libraries. Community support is available via forums, IRC and an issue tracker.

Aegisub is distributed under an open‑source license, remains in a stable maturity stage, and can be compiled from the repository using the provided build scripts. It bundles optional components such as Avisynth and VSFilter, and includes an automation directory for extending functionality.