Legato Systems Inc. (Nasdaq: LGTO) last Friday said that it is suing competitor NSI Software for patent infringement, one of the latest lawsuits in the software industry (see Legato Sues NSI).
The software vendor filed the suit in the Northern District of California Federal District Court in San Jose on May 15, charging that NSI willfully infringed on two of its patents, U.S. Patent Nos. 5,799,141 and 6,308,283.
The first patent was filed by the Qualix Group Inc. in 1995. After acquiring that company, Legato filed the second patent, a continuation patent, in 1998. Legato uses the patented technology in its file-replication software, RepliStor, formerly known as Octopus. The technology, according to the company, enables asynchronous, real-time data replication, allowing for the simple creation of more than one copy of Windows data across LAN and WAN environments (see Legato Bundles Continuity Apps).
Legato claims that NSI has integrated the two disputed patents into its popular Double-Take data replication software (see NSI Eyes Europe With Sunbelt, NSI Wins IBM Approval, and NSI Stalks Windows NAS).
The issues, say intellectual property experts, are whether NSI's software actually performs functions covered by Legato's patents and whether there are prior claims on the technology. "The question is: How were people providing mirroring of files... before the 1995 patent was filed?" says Yar Chaikovsky, an intellectual property attorney at Weil Gotshal & Manges LLP, pointing out that NSI will probably try to establish that the technology was being used prior to the patent filing. "The older these patents get, the more difficult it is to find the [unpatented] prior art."