Some time ago I complained about Google desktop search. It's installation sucked so much I was not able to install it.

The other contender from a big software company came some time after that - Microsoft launched Windows Desktop Search. I decided to give it a try; after all, which company could achieve better OS integration than Microsoft? I have also heard about IFilter interface that should be a simple way to allow developers to open their custom documents up to the indexer.

After using it for about 4 months, I gave up. The app is a memory hog. It is not obtrusive in that it waits for your inactivity to do the indexing, but even when idle it consumes non-trivial amounts of memory. I would have ignored this if the results of search came quickly and were easy to read. Neither were satisfactory though - search would take several seconds longer than you'd expect and the result were very unreadable - despite the setting to highlight the words searched for inside the document you're looking at this did not work. On top of all this the result viewer felt very slow and the results were always sorted by some magical and totally unusable method (instead of by relevance).

But there is one desktop search app that is worth your attention: Copernic Desktop Search. You might remember Copernic from before when they had various Internet search related products. You get basically the same package as with other desktop search products except that this one works well. Indexing is unobtrusive, search is fast and all the result keywords are clearly highlighted on each and every matched document. It indexes the same kind of documents like all the competitors and actually has better extensibility model for the .NET developers than Microsoft! Highly recommended.