Irvine-based Stack Computer, a technology integrator focused on the storage industry, has been acquired by Boca Raton, Flordia-based Agilisys. The deal was worth $28M in cash, and closed yesterday. Stack services customers in the financial services, healthcare and manufacturing industries, and specializes in storage area networking products from Cisco, Veritas, and EMC. According to Agilisys, Stack had annual revenues of approximately $55M.