Keyword Stemming Question

Which SE's stem keywords?

[CanadianChris]

I'm 99% positive that Google stems keywords when doing searches, but I'm not sure about Yahoo or MSN, anybody know?

Ex: "widgets" returns results for "widget" as well as "widgets"

[fischermx]

All big search engine does stemming while crawling.
Though not exactly while doing the search on the index.
I would guess they save both the stemmed and the original keyword in their index.

Take a look and ask why you get different results, for example, with and without the plural form of word.

At google :
Databases : 37,000,000
Database : 164,000,000