The Arcati Mainframe Yearbook 2007

As a picture tells more than a thousand words, here's a chart from the annual survey Arcati does among mainframe customers :
In fact I added the 2005 chart to compare with the current situation. I know there is some delay between survey and publication, but still, it suprises me that still 33% of the respondents is on z/OS 1.4 (59% in 2005, 48% in 2006), keeping in mind z/OS 1.4 is End of Support by the end of the month.
This is just one of the many charts of the user survey Arcati publishes in its 'Arcati Mainframe yearbook 2007'. There're others on annual MIPS growth, mainframe processors installed (z9EC+BC represent 26%), use of middleware, SOA . . .
But there's a lot more in this 147 page free download than just this survey. There are some 10 articles on various subjects, such as 'Problems with worldwide pricing variations', 'Harnessing the power of legacy systems' and 'Modernize you systems with XML'.
There's a vendor directory listing vendors, consultants and service providers in the z/OS and OS/390 environment. There's a media guide for IBM mainframers listing lots of useful links and information sources, even a few blogs - no not mine ... yet ;-).
It concludes with a glossary, some historical data and technical hardware tables of the z9 (including MSUs, MIPS and MSU/MIPS ratio).