IBM has agreed to pay approximately $2.1 billion in cash or $10.50 per share for Rational, which specializes in software-development tools. Rational will now become the fifth brand in IBM Software ...

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Big Blue plans to pay $2.1 billion in cash for Rational Software, the leading seller of tools to create models of applications and databases before programmers actually start coding. Martin LaMonica ...

NEW YORK -- IBM Corp. said Friday it will purchase Rational Software Corp., a maker of development tools, for $2.1 billion in cash -- its biggest software acquisition since purchasing Lotus in 1995.