I'm looking for a GUI-based text/log viewer that will allow to only display lines that contain particular phrases/words/characters. The logs may not necessarily by OS related but from 3rd party applications.
One suggestion is "glogg", it's available as an Ubuntu package and doesn't have nasty dependencies (Qt4-based).
Another one is ksystemlog, not sure if it does filtering as you require.
Finally I have to ask, why does it have to be GUI? Personally I'd use the old:
there's also swatch which is possibly nicer, though I have never used it.