JSubber is released under the GNU General Public Licence (GLPv3), and can be used and distributed freely, according to the terms of this licence.
To run JSubber you will need to have Java installed (at least version 5) which is available at java.com
JSubber allows you to easily create subtitles (SRT format) while watching a video. These subtitles can then be easily uploaded onto YouTube or DailyMotion videos (among others).
The subtitles can also be easily converted to other formats and/or manipulated by using SubtitleWorkshop.