Forrester has published a report on Dec 30, 2009, providing an overview of middleware software market. It has reported total market size for middleware software at $25 billion plus for year 2008. The middleware software includes business process platforms and legacy transaction servers (e.g IBM CICS, Oracle Tuxedo, Natural/Adabas etc). As per the report, IBM is market leader with 18.7% market share. It is followed by Microsoft (16.3%), Oracle (13.8%) and SAP (5.4%). These top four vendors cover 54.2% market share. Software AG, TIBCO Software and Progress Software are the leading three independent vendors focused on a middleware portfolio. Their market shares are 2.2%, 2.1% and 1.4% respectively. Red Hat is only holding 0.2% market share though "usage" share for open source software could be more.