monline

I don't know how did this not get into jEdit's core. It's really a must have.

It's a BeanShell macro. Filters lines of a buffer by matching them against a regular expression.

The filter actions are: remove in current buffer or write to a new buffer.
The filter is applied on: matching or not matching lines.
The filter works on: the whole buffer or the selection (if it spans over more than one line).