According to Ross Mauri, IBM's General Manager of System z, and Mark Shuttleworth, Canonical and Ubuntu's founder, this move came about because of customer demand. For over a decade, Red Hat Enterprise Linux (RHEL) and SUSE Linux Enterprise Server (SLES) were the only supported IBM mainframe Linux distributions.
As Ubuntu matured, more and more businesses turned to it for the enterprise Linux, and more and more of them wanted it on IBM big iron hardware. In particular, banks wanted Ubuntu there. Soon, financial CIOs will have their wish granted.
In an interview Shuttleworth said that Ubuntu Linux will be available on the mainframe by April 2016 in the next long-term support version of Ubuntu: Ubuntu 16.04. Canonical and IBM already took the first move in this direction in late 2014 by bringing Ubuntu to IBM's POWER architecture.
Before that, Canonical and IBM almost signed the dotted line to bring Ubuntu to IBM mainframes in 2011 but that deal was never finalized. This time, it's happening.
Jane Silber, Canonical's CEO, explained in a statement, "Our expansion of Ubuntu platform support to IBM z Systems is a recognition of the number of customers that count on z Systems to run their businesses, and the maturity the hybrid cloud is reaching in the marketplace.
With support of z Systems, including LinuxONE, Canonical is also expanding our relationship with IBM, building on our support for the POWER architecture and OpenPOWER ecosystem. Just as Power Systems clients are now benefiting from the scaleout capabilities of Ubuntu, and our agile development process which results in first to market support of new technologies such as CAPI (Coherent Accelerator Processor Interface) on POWER8, z Systems clients can expect the same rapid rollout of technology advancements, and benefit from Juju and our other cloud tools to enable faster delivery of new services to end users. In addition, our collaboration with IBM includes the enablement of scale-out deployment of many IBM software solutions with Juju Charms. Mainframe clients will delight in having a wealth of 'charmed' IBM solutions, other software provider products, and open source solutions, deployable on mainframes via Juju.
Shuttleworth expects Ubuntu on z to be very successful. "It's blazingly fast, and with its support for OpenStack, people who want exceptional cloud region performance will be very happy.