Microsoft is upping its ante to corner a share from IBM's mainframe business as it invests an undisclosed amount in French software maker TurboHercules which has hogged limelight for filing an antitrust complaint with EU against IBM.

TurboHercules SAS is a maker of mainframe applications which can run on non-mainframe systems. It uses Hercules, an open-source software implementation of IBM's mainframe architecture. It enables users to run mainframe applications on hardware platforms which are powered by Intel and AMD processors.

TurboHercules filed an anticompetitive complaint against IBM in March charging it of restricting customers from running non-IBM mainframe applications on IBM mainframe hardware which results in vendor lock-in.

The mainframe software market which is valued at around $25 billion has been in flux as a number of small companies have pushed anti-trust motion against IBM. The list of companies included Platform Solutions Inc. (PSI), Neon Systems and T3. PSI was ultimately acquired by IBM in 2008. Microsoft had made investments in both T3 and PSI.

Roger Bowler, Hercules Creator/ TurboHercules Co-founder, stated in a blog entry in March: By IBM's own estimation, $5 trillion worth of applications run on IBM mainframes. These highly proprietary applications, which have typically been developed over many years and embed an incalculable wealth of company-specific business knowledge, cannot be easily migrated to other platforms.

He also cited that currently IBM holds 100 percent of IBM-compatible mainframe market and is the only vendor in the world allowed to sell hardware systems compatible with applications that run on its vast suite of mainframe software (e.g. z/OS, z/VM, CICS, IMS, DB2).

The primary motivation of TurboHercules in filing the antitrust motion is to help return to the competitive market for mainframe technologies that existed in the '80s and '90s, where IBM licensed its operating systems to customers of the Plug Compatible Mainframe (PCM) manufacturers such as Hitachi and Fujitsu/Amdahl.

Microsoft said in a statement that its investment in TurboHercules is in support of eliciting greater openness in the mainframe market.

A major chunk of Mainframe applications still use native mainframe OS and languages such as COBOL, PL/I.

EU initiated formal antitrust investigations against IBM in July focusing on cases filed by emulator software makers T3 and TurboHercules and a second case involving IBM's alleged discriminatory behavior towards competing suppliers of mainframe maintenance services whereby it is charged with restricting and delaying access to spare parts to maintenance service providers.

In 2009, about 8.5 billion euros worldwide and 3 billion euros in the European Economic Area were spent on new mainframe hardware and operating systems, the EU said in a statement in July.

While Microsoft has its own program that allows migration of workload from mainframes to Windows Server System, it seems now Microsoft is utilizing the smaller companies to make a dent into the market ruled by IBM.