Last month I talked to a couple of vendors who are making new inroads in the services arena through open source offerings. Open source support in Web services is definitely very heartening. While the frameworks and utilities for implementing Web services in enterprise applications have matured, the standards of critical functions of promoting the "service bus" concept, which decouples Web services from the realization of an SOA, and the effective deployment and management of services, are still evolving. ESB as a concept has caught on very well in architecture discussions and vision, but I haven't seen too many examples of where large enterprises have actually implemented the design in their applications.

One of the main reasons for this is the fact that although ESB is offered by the prevalent applications server, messaging, and other "plumbing" vendors, it is only recently that implementations from the community have made their way into the industry. The way a technology usually makes inroads into an organization (at least medium sized, where commercial vendors don't have a monopoly) is through open source offerings. For example, frameworks such as Struts and Axis are not just the de facto standards, but are also the most widely adopted standards. Every app server vendor who has any presence in the market supports them.

Web services have matured to a level where their build and maintenance are becoming a part of the traditional SDLC. Going into the build and project management space, Maven is one of the prime examples of how the open source offerings were packaged to enable the process instead of just the technology. Maven utilizes Ant for build management, JUnit for unit testing, Jalopy for formatting source code, Checkstyle for validating Java source against a coding standard, and Sun's javadoc for standard JDK code documentation. One of the vendors I mentioned at the beginning of this document, Mergere, has leveraged the Maven and Continuum project to create a software build and orchestration platform for Web services. Mergere created an offering to leverage best practices in the form of tools that create a build automation dashboard for services.

The other vendor that I talked to, LogicBlaze, is focused on a technology layer in the services stack - ESB. While ESB implementations are available from a few vendors, as I mentioned earlier, the application of the bus in enterprise applications is still rare. One of the main challenges is the lack of standard APIs to enable a protocol-agnostic interface to the bus, without which the concept of a ubiquitous enterprise bus is hard to digest. The JBI spec, announced in June at JavaOne 2005, attempts to address this problem. The latest release of ServiceMix (2.0), the open source product from LogicBlaze, leverages JBI in its ESB offering.

While open source offerings from vendors facilitate the adoption of products that enable service-orientation in enterprise applications, their acceptance in large organizations is still lagging. This is because of the same reason that has plagued adoption of open source from the start - support. Although the products are adequately supported through a community, dedicated professional services and support groups that businesses can bank their business on are not generally available. As a result, open source products are leveraged in organization through commercial vendor toolsets or for non-production environments.

Partnerships are needed between vendors with open source offerings and system integrators that offer professional services to large clients. System integrators can offer the missing link to enable adoption of economical options to expensive vendor offerings in large organizations.