IBM Buying Kenexa

Kenexa’s stock is up about 40% early today on news IBM’s buying the company for about $1.3 billion.

IBM says it’s buying Kenexa to bolster “social business initiatives.” IBM tells me that Rudy Karsan, the well-regarded founder and CEO of Kenexa, will stay with the new company.

Kenexa has a mix of products and services, from RPO to applicant tracking systems (through its BrassRing product).