PartsBox has a fuzzy-matching search engine that is designed to match electronic components well. It tolerates a certain amount of misspellings and still gets the right results. And most importantly, it runs right in the browser, and also happens to be really fast. So fast that it provides instant results, no need to even press ENTER after typing your query.
Fuzzy-matching is great for electronic parts. For example, searching for '61a20dwp' will bring up the TPA6120A2DWP which you really wanted, and typing 'mcp78381' will show the MCP73832T-2ACI/OT that you have in stock.
The search engine indexes component names, descriptions, footprints and user notes, as well as custom fields. If a local part number is assigned, both MPN (Manufacturer Part Number) and company part number are indexed, and both can be used to find the part.
Additionally, apart from fuzzy matching, the search engine also supports exact filtering by tags. These are entered with a '#' character in front, for example '#smd'. If you use a tag in your query, results will be narrowed down to only those parts that have exactly that tag (or several tags).
As an example, a search for '4k7 #0402 #resistor' will first retrieve the parts which have both the '#resistor' and '#0402' tags, and then do a fuzzy search for '4k7'.