Welcome. My name is Martin Keen and I'm delighted to be your instructor as we explore how open standards are implemented in a z/OS system by z/OS UNIX. We're going to be looking at all aspects from this, from the file system to the shell and beyond. And you'll get your chance to get your hands dirty with a series of lab exercises using a real IBM Z UNIX system. To try out the concepts that we will be covering here, so let's get cracking. Now, z/OS UNIX brings together the open world and the z/OS world. Both worlds can co-exist independently while sharing the same processing and storage resources. It's a case of getting the best of both worlds; a standard interface and portability from the open part of z/OS UNIX, and a large array of services from the MVS part of z/OS. z/OS UNIX supports an environment of large operating systems or servers, distributed systems, and workstations that share common interfaces. z/OS UNIX supports the set of standards being developed by the Open Group. This includes the Portable Operating System Interface, better known as POSIX. Users can concentrate their work in the environment where they're most comfortable, be that UNIX or be that MVS. For example, application developers can develop most of their applications at their workstations, and then use standard POSIX interfaces to compile, test, and debug their programs on the z/OS system. Currently, in US applications normally run as usual. Current users continue to have all of the services of z/OS available. And with z/OS UNIX, the existing investment in z/OS applications and data is protected. New applications will have access to existing data. Now, what are open systems? Based on requirements from customers, the characteristics of an open system environment can be expressed by the following elements. First off, there's portability. This is the ability to relocate system resources such as applications, data, and people, between processing environments of different design and different architectures. There's also interoperability. This defines the ability to interconnect systems from different vendors and have them work together, to solve a business problem. And finding there's investment protection, which is the ability to choose components from offerings of many vendors, many protocols and many architectures or with the confidence that they're going to work together. In an open system environment, a set of standards can provide the ability to interoperate and to port applications, data and people, on different operating platforms. The vendor names that we're showing here, they're just an example, but the point is, it's this defined set of standards in the middle, that enable interoperability and portability of applications. There are two types of standards. There are de facto standards, and de jure standards. De facto standards, those are established by broad industry usage of a technology. De jure standards are established and accepted by recognized standard bodies through a formal voting process. The Single UNIX Specification or SUS, is the collective name of a family of standards for computer operating systems, compliance with which is required to qualify for using the UNIX trademark. If an operating system is submitted to the Open Group for certification and passes conformance tests, then is deemed to be a compliant UNIX standard. z/OS UNIX meets these open systems requirements. UNIX applications which conform to XPG 4.2 standards can be ported to z/OS. These can be vendor applications or self-developed applications. Does this mean that every UNIX application should run on z? Well, of course not. But, applications that require true enterprise server qualities of service, they are well suited. If your application is high, does the requirements, high security needs or needs a high level of reliability, then you'll see a lot of benefit in moving that application to z/OS UNIX. In the next video, we'll take a look at how UNIX is implemented with z/OS.