According to IDC's Worldwide Quarterly Storage Software Tracker, the worldwide storage software market grew 14.9% year over year to $2.1 billion in the first quarter of 2005, marking the sixth consecutive quarter of double-digit year-over-year growth. "Continued customer spending on software for data protection, storage resource management, and compliance, has helped to drive this positive start to 2005," said Rhoda Phillips, research manager for IDC Storage Software. "Spending growth related to data protection, including replication, backup, and archive software, is an indicator of customers' continued concerns about application availability, data management, and business continuity." In the first quarter of 2005, the storage resource management and the back-up and archive software markets continued to represent the two largest storage software markets, each representing a third of the market. The storage replication software market also enjoyed strong results in the first quarter with 19.7% year-over-year growth. The file systems software market grew 25.4% year over year. EMC led the overall market with 30.0% revenue share in the first quarter of 2005. VERITAS maintained its second position with 21.4% revenue share, growing 11.4% year over year. IBM finished in the third position with 8.6% revenue share. Network Appliance and HP rounded out the top 5 in a statistical tie with 6.7% and 6.6% revenue share, respectively. Network Appliance and EMC posted the strongest results among the top 5 vendors, with 61.1% and 17.9% year-over-year growth, respectively.