It's now possible to migrate an existing system to .NET with little reengineering, while preserving scalability and positioning the migrated application to implement Web services and SOA. The most promising solution may be an enhanced version of RPG that is both MSIL compliant and fully object oriented. By migrating to such a language, the organization can leverage the skills and knowledge of its engineering staff - allowing the RPG programmers, who possess intimate knowledge of the applications and processes, to develop new Windows and Web-based applications. In addition, because the new language is MSIL compliant, RPG programmers and MSIL programmers (VB, VS, C#, and so forth) can work together on the same projects. The language bridges platforms both on the technological and the human level.

For implementation of Web services and service-oriented architectures, the availability of an MSIL-compliant RPG language provides a vital link. It ensures that the RPG applications participate in .NET, which in turn supports all of the standards - WDSL, XML, and so on - that enable Web services and SOA. Through such a language, RPG applications can fully participate in Web services and be modernized to and included in an SOA, while retaining the skills and knowledge of existing programming resource (RPG as well as OO), and without rewriting or re-hosting the applications. In other words, the iSeries and each of the pillars that supports both the IT system and the organization - the RPG programming support staff, the critical iSeries business applications, the inherent business processes they support, and the data that resides on the iSeries - can be transformed into a modernized, Web-enabled system, thanks to tools that bridge the iSeries/RPG and .NET.

In addition, an SOA, once implemented through an MSIL-compliant language, provides an elegant path to modernization that no other technology or methodology has accomplished to date. By encapsulating business functions performed in the legacy environment inside Web services, a company can now leverage the investment in the business system while making it available to other heterogeneous environments. Furthermore, using the SOA model, a company can extend those parts of their legacy application that they need over a time frame that makes the most business sense to them.

Checking the "MAP"
In 2004, Microsoft teamed with nine iSeries service providers and ISVs in an alliance - the "Midrange Alliance" - intended to encourage iSeries shops to consider a variety of alternatives when they modernize. The project was spearheaded by ASNA - a longtime iSeries vendor that markets extension, modernization, and migration software products, including ASNA Visual RPG, an MSIL-compliant, fully object-oriented RPG language, and its Monarch product, an iSeries/400 to .NET replatforming analysis and transformation solution. The Midrange Alliance, which now has 19 members, provides resources for organizations planning modernization efforts on their Web site, including case studies, white papers, and pertinent information on IBM, Microsoft, and third-party products. Although the alliance may have a reputation for offering migration-only options, members, which include ASNA and LANSA, another founding member, also provide solutions for organizations that want to retain sensible loyalty to the iSeries.

Summary and Evaluation
For the six modernization options listed earlier, we can now provide a concise summary: the first two, replace or rewrite applications and RPG/400 emulation, are not sensible approaches to modernization, if they could be considered modernization at all. Screen scraping creates the look of modernization without doing so in reality, and in fact results in programs that resist modernization. Host-based ad hoc systems bind the organization to proprietary, nonstandard technologies and remove maintenance, enhancements, and capabilities from the organization to the vendor. Language conversion results in the loss of the original RPG developers (and their "tribal knowledge") and in code that is difficult to maintain for RPG and Java or C# developers alike.

Platform transformation tools, such as an MSIL-compliant RPG language, offer the greatest promise for meeting the challenges of modernization: bringing the enterprise system into the 21st century while avoiding unnecessary or costly disruption to the business. In short, it provides the best means of managing costs and achieving a reasonable timeline while making the most of opportunities that leverage an organization's assets.