We've been doing exactly this for our antispam app, we started off with a working custom filters web app (Angularjs) which you can see at http://209.213.221.169

We've been doing exactly this for our antispam app, we started off with a working custom filters web app (Angularjs) which you can see at http://209.213.221.169:8080/ http://209.213.221.169:8080/ using text or regular expressions (the regexp has a bug in it). This also shows the query in plain english as you build the query. Original design credits for the test app to https://github.com/kindohm/knockout-query-builder/ https://github.com/kindohm/knockout-query-builder/ This is the design we've come up with so far, which incorporates grouping of queries. We've tried to make it readable, but we also display the query in a sentence as you build it. http://cdn.firetrust.com/images/misc/customfilter.jpg http://cdn.firetrust.com/images/misc/customfilter.jpg