Terms of the deal, announced on Wednesday at the ManageFusion conference in Las Vegas, were not disclosed.
Palo Alto, Calif.-based AppStream had been partnering with Symantec for two years. AppStream's offerings, which lets customers deploy and manage applications, are currently being integrated as part of Symantec's virtualization portfolio.
The buy follows on the heels of Big Yellow's $830 million purchase last year of Altiris, provider of virtualization software management.
The AppStream deal is expected to close this summer.