English - Windows version 3.02 reviewed 2016-08-13 (with a few edits 2016-08-21 for clarity)
In the Reaper forum there was discussion about enhancing the media browser, which has some good features, but at version 5.20 is still somewhat minimal. A contributor suggested Crypton Mutant so I came here and tried it out.
This one really has some excellent features, and as it is currently free it's unbeatable. With a few tweaks and enhancements I would be glad to pay to support the developers a little more. Sonicwire is a soundware vendor so I think the intention is that the Mutant browser can take you to Sonicwire when you are browsing for sounds. Fortunately the integration is passive and there is no need to sign up with Sonicwire to manage your local sound libraries.
The description on the the Details page is pretty accurate. I'm just going to add some remarks of my own that go beyond it.
The sounds database appears to be kept in memory first, then managed in My Documents / Crypton / Mutant / Mutant_db / Mutant.db with an XML file storing the column widths, audio file types., etc.
I moved the executable there and it still works fine. You can create as many dbs as you want but they will all be in the Crypton folder.
Truly free as far as I can tell; not crippleware, etc.
Simple, logical/conventional GUI operation.
Allows adding tags and user memos to samples and loops (extremely helpful for me).
It has a nice feature where length of sample, besides showing in mm:ss in length column is indicated by the length of a transparent bar over the entry row. Waveform of sample is also displayed.
Fast to build database: On a Intel Core 2 Quad based windows 7 system (not at all the most recent) took about 5 min to add 5700 samples then another 15 or 20 minutes more to add another 42000.
The database for 77000 items is only about 35 MB.
Search is extremely fast and has simple boolean operators and, or and not (and: space between strings, or = | between strings, not = - before string).
My biggest disappointment is that only sounds within current folder are displayed. Would be nice to have the option of displaying all sounds within current folder and subfolders. Although Search is very fast, it searches over all files in the database which may return a lot of hits.
In the found items list, you need to look at a sample's Properties to see which folder it is in.
Some typos/inheritances from Japanese in English GUI and manual -- these don't affect operation.
Allow display of all samples (hack for this is to a Boolean that covers everything: if you enter "-?" in the Search box it finds all the items that don't have ? in the name (or in tags).