On the 21st GOTD offered the Joyoshare Media Cutter, which sort of hinted that it could perform lossless cut editing. In case anyone is interested in this sort of thing, here's a little bit more info...
Normally when editing video: clips are arranged, shortened as needed, transitions applied whenever 2 clips meet, any FX &/or color correction applied, and the whole thing rendered to a newly encoded video file. Because the video has to be re-compressed [re-encoded], there's some unavoidable quality loss -- pros counter this by shooting video at a higher resolution than their expected final output, so it's a fact of life, no big deal sort of thing. You're not likely to find pro level software that allows lossless editing, because there's not a big market for it.
A hobbyist OTOH may want to work with video that's not shot using pro, hi-rez gear, or reuse/repurpose whatever video they can get their hands on, and some are interested in preserving as much quality as possible. And when/where possible they might use software that can perform cut editing, meaning no transitions, FX etc., without re-encoding, so quality stays just the same, before & after.
One way that gets complicated is that different video compression methods or formats store data differently -- even color -- so all of the video used has to be exactly the same format using the same encoding settings. Another complication is that some formats work Much better than others. Most video uses some form of key frames, which are complete images, with frames in between key frames storing just the data on what's changed. With very few exceptions, you can only cut or splice video files at key frames, so how often those key frames appear matters -- some web video may have Very few.
Another complication is the video file structure, since formats store data like the last frame's time in different places & ways in the video file -- after editing that data has to be changed to reflect the new values. Related, some formats may not store timing information at all, or only if there's audio combined with the video in the file.
Videohelp[.]com has a few apps listed that can do lossless video cutting & joining, but they tend to specialize on only a single video format. Windows media format had support for lossless editing built in, but it's rarely been exploited or included in any software. Older versions of Vegas & Nero video supported lossless editing for some formats, though with Nero the video had to have been encoded in Nero originally. Like the specialized Womble apps, with DVD mpg2 they could re-encode just those portions of the video that had to be re-encoded, just copying the rest to a new file. It was/is tricky though, e.g. audio often had to be converted to .wav & re-compressed afterward -- I found it more reliable & faster to just edit the DVD playlist, skipping over video I didn't want played.
You can try to do simple cuts with tsMuxeR, & you can use ffmpeg for lossless joining, but it's not for the faint of heart.
trac[.]ffmpeg[.]org/wiki/Concatenate