<< Highlighted below are 10 popular open source projects that
enterprises can look to when considering open source alternatives in
their IT infrastructure. I've highlighted a few key open source
components in some of the most asked-for categories - Web Services,
Service Oriented Architecture (SOA), Integration, Frameworks, and
Libraries. Each project selected has at least one vendor offering
commercial support. At the end of this article, I'll offer a basic
checklist for those who are evaluating open source to ensure that the
open source software they select fills all of their technical and
business-related needs while managing corporate risk.
Web Services
XFire
XFire is a Web Services framework (hosted by Codehaus) that allows
developers to create and/or consume Web Services. Given its simplicity
of use and built-in testing tools, it makes short work of Web Services
by effectively eliminating the manual labor of generating WSDL and
other artifacts of SOAP. XFire is compatible with a variety of
commercial and open source Web Services frameworks, including Apache
Axis and Microsoft Web Services.
Major pros of this relatively new project are that it's up-to-date,
fast, built to integrate with other frameworks like ServiceMix, and
supports JAX-WS - an easy-to-understand architecture for Web Services
development that can be used to build Web applications and Web
Services with newer XML-based functionality.
However, because XFire is so new, many organizations have already
become comfortable using Apache Axis - the original open source Web
Services offering. Companies might feel more comfortable choosing Axis
over XFire simply because of name recognition.
The license for Xfire isn't an OSI-approved license but it is very
liberal, only requiring a copyright notice. Xfire is in the process of
merging with Celtix, backed by Iona Technologies. Envoi Solutions and
OpenLogic offer commercial support.
Axis2
Similar in function to XFire, Axis2 is a core engine for Web Services.
Like XFire, Axis2 supports SOAP and other standards, but it also has
integrated support for the Representational State Transfer (REST)
style of Web Services. Axis2 is a more efficient, modular, faster, and
more XML-oriented (it has the new fast AXIOM XML parser) solution than
the original version. It supports plug-in modules that extend
functionality for features such as security and reliability, factors
critical to enterprise IT.
The primary downside of Axis2 is that it's plagued by the stigma of
the first Axis, which has the reputation of being poorly documented
and difficult to use. However, Axis2 does offer more documentation,
which is a marked improvement over the earlier version.
Axis2 is an Apache Software Foundation project and is available under
the Apache 2.0 license. Commercial support is available from several
companies including Covalent, OpenLogic, and WSO2.
Choosing between Axis2 and XFire really comes down to what you need to
plug into. XFire is meant to be easily pluggable and work with a slew
of other frameworks, including ServiceMix, while Axis2 is better
suited for standalone use, although it's also pluggable if necessary.
These two offer less expensive open source alternatives to proprietary
Web Services solutions like those offered by Microsoft. Unless
companies are using a full-blown SOA implementation where they get
everything from a vendor (BEA, for example), they would probably want
to opt for an open source solution like these two for reasons of cost
and simplicity.
SOA
ActiveMQ
ActiveMQ is the most popular and powerful open source Message Broker.
Although not quite a full-blown SOA solution, its flexible messaging
technology is required for any SOA implementation. Widely considered
one of the best Java Messaging Service (JMS) implementations
available, ActiveMQ is fast, pluggable, and easy to embed into
homegrown software, especially Spring-based applications. It's easily
manageable through JMX, and it works with Apache Axis2 and XFire as
well as servers like JBoss, WebLogic, and Geronimo. It also supports
REST, many cross-language clients and protocols, including Java, C,
C++, Perl, PHP, Ruby, and Python, and a wide variety of transport
protocols. Regarding functionality, ActiveMQ provides a number of
advanced messaging services offered by commercial vendors, such as
Message Groups, Virtual Destinations, Wildcards, and Composite
Destinations.
The drawback with ActiveMQ is that it's still fairly young and
evolving, so it might require heavier configuration rework than
enterprise developers want to accept. Although this extreme
configurability is a major asset of ActiveMQ, it requires time to
configure correctly for your circumstances.
ActiveMQ is an Apache Software Foundation project and available under
the Apache 2.0 license. Commercial support is available from
LogicBlaze and OpenLogic.
ServiceMix
This project provides an Enterprise Service Bus (ESB) that combines
the functionality of a Service Oriented Architecture (SOA) and an
Event Driven Architecture (EDA) to create an agile enterprise ESB.
It's built on Java Business Integration (JBI) and supports BPEL in
conjunction with rules engines. It has dozens of transports and
plug-ins and is lightweight, easily embeddable, and offers integrated
Spring support. It works standalone or within Geronimo or JBoss and
sits on top of ActiveMQ. It has e-mail integration, Web Service
integration, virtual file system integration, XSLT transformation,
content-based routing, and Groovy support for end-point scripting.
ServiceMix is the most configurable and adaptable open source ESB
implementation available. Like ActiveMQ, though, ServiceMix's
configurability is a blessing and a bane. The project is still young,
and it will go through many iterations and require a lot of
configuration by developers. Also these open source alternatives don't
offer a lot of user interfaces for policy administration, management,
control, flow design, or the other bells and whistles offered by
commercial competitors like Sonic and BEA.
ServiceMix is an Apache Software Foundation project and is available
under the Apache 2.0 license. Commercial support is available from
LogicBlaze and OpenLogic.
Integration
POI
Java-based POI gives developers easy and direct access to Microsoft
Office files, including Word and Excel. The documents can be parsed
and generated, which makes it easy to create them on-the-fly for
downloading purposes from a corporate Web site. So, if a developer
needs to create a report that's required on the business end in Excel
or Word, POI is the open source tool of choice.
Unfortunately, although it's top-notch for reading Word or Excel
files, it currently can only create Excel files. The functionality to
create Word files is reportedly in development.
POI is part of the Apache Software Foundation's Jakarta Project and is
available under the Apache 2.0 license. Commercial support is
available from OpenLogic.
iText
This library lets Java developers create PDF files (without shelling
out big bucks to Adobe for a PDF writer). Unlike HTML, which is
browser-dependent, iText allows generation of read-only,
platform-independent documents containing text, lists, tables, and
images. Generally, iText is best used for Web sites that need to
generate on-the-fly PDFs with the aforementioned elements. It's used
by BIRT (Business Intelligence Reporting Tools, a recent addition to
Eclipse) and other reporting tools to create downloadable PDF versions
of their generated reports. There are no significant drawbacks to
using this tool.
iText is available under the Mozilla Public License or LGPL.
Commercial support is available from OpenLogic.
Frameworks
Hibernate
Hibernate is considered the object relational mapping tool of choice
for Java developers. It's full-featured, robust, supported, well
tested, updated, and heavily used in the enterprise. Hibernate is a
critical component of Red Hat's JBoss Enterprise Middleware System
(JEMS), which comes with extensive professional support, consulting,
and training services. Hibernate supports over a dozen databases,
including Oracle, DB2, MySQL, and PostgreSQL and also works either
standalone or in conjunction with application servers like Geronimo
and JBoss. It's highly configurable for performance tuning, offers a
sophisticated caching mechanism, and has generation tools so one can
generate database schemas from Java objects (or vice versa) or
generate both from a mapping file that describes how the Java objects
are to be persisted in the database. It also lets you drop to native
SQL if the standard Hibernate Query Language (HQL) is insufficient.
There is currently a pending patent infringement suit filed by
Firestar against Red Hat over Hibernate's technology. Although the
tool itself is solid and many people believe the lawsuit is without
merit, enterprises should take this into account when selecting this tool.
Hibernate is available under the LGPL. Commercial support is available
from a variety of companies including OpenLogic and Red Hat.
Spring
Spring, available under the Apache License, is a highly configurable,
lightweight, aspect-oriented, flexible application framework that can
be used as an alternative to heavy J2EE applications. It can work
standalone or in conjunction with application servers like JBoss or
Geronimo. The big claim to fame for Spring is that it supports
dependency injection and inversion of control, which means that
business objects don't have to know all of the details of system
configuration a priori; instead, Spring configures applications at
start-up time by injecting each object with its necessary
dependencies. This creates a very loosely coupled system that can be
easily configured through XML whereby one can tune and reconfigure
just by changing the XML description and without modifying the
underlying code. This is quite valuable when transitioning from a
development environment to QA to production where database connection
parameters change, clustering is introduced, and other configuration
properties need to be modified.
Spring is compatible with many of the other projects already
discussed, including XFire, ActiveMQ, ServiceMix, and Hibernate. The
only downside with Spring is that all those configuration parameters
amount to vast expanses of XML. Without some upfront thought into your
configuration strategy, all that uncompilable XML can get out of hand.
Spring is available under the Apache 2.0 license. Commercial support
is available from Interface21 and OpenLogic.
Libraries
JUnit
JUnit, released under the Common Public License Version 1.0 and hosted
on SourceForge, is the de facto standard for unit testing in the Java
development world. It supports agile methodologies and makes it easy
to blend testing infrastructure into build tools and environments so
that developers can quickly see if a change they have made will break
the code base. It integrates well into Ant and Maven, the two most
popular open source build tools for Java developers, and Eclipse, the
most popular IDE. JUnit can also work both in standalone mode through
a command line and through its own user interface to display results.
In either case, errors and failures are reported clearly (with
optional HTML output through integration with Ant) so developers know
exactly where to look for problems.
JUnit is available under the Common Public License. Commercial support
is available from OpenLogic.
Jakarta Commons
Jakarta Commons is a three-part project focused on reusable Java
components and is already heavily used at the enterprise level. The
Commons Proper, a repository of reusable Java components, the Commons
Sandbox, a workspace for Java component developers, and the Common
Dormant, a repository for inactive Sandbox components, make up Jakarta
Commons. The Commons is a great default library for enterprise
developers that covers a range of basic development needs, from
configuration support to logging to programmatic HTTP access to
Command Line Interface (CLI) parsing to database connection pulling to
e-mail generation to XSLT processing. It offers a solid base layer for
every enterprise developer to look at instead of creating
task-specific widgets - the fact is they can probably find what they
need in Jakarta Commons.
The potential downside is that a lot of tools remain in the sandbox,
meaning they're subject to change. For developers, this could mean
needing to rewrite code in the future, which can be time-consuming.
Jakarta Commons is an Apache Software Foundation project and available
under the Apache 2.0 license. Commercial support is available from
OpenLogic.
Conclusion
Obviously, neither the list of 10 products above nor the evaluation is
all-inclusive. For every project mentioned, there are others that do
the same tasks. That being said, open source often fights an uphill
battle with respect to enterprise adoption largely due to the
inaccurate perception that it is more complicated and less reliable
than proprietary offerings. However, with the proper due diligence,
enterprises can ensure that the open source projects they select are
reliable, proven, and supported. And while only a fraction of the
144,000 open source projects on SourceForge may meet this stringent
enterprise litmus test, many have matured, been battle-tested, and
serve as legitimate alternatives to proprietary software in
business-critical environments.
Checklist for Evaluating Open Source
Evaluating open source projects requires the same due diligence as
reviewing commercial and proprietary solutions. Thus, there are two
key areas to evaluate: functional and technical capabilities, and the
ecosystem of services around the product (support, maintenance,
community, commercial backing, etc.). With traditional proprietary
commercial products, there is a vendor (along with partners) that
typically provides the ecosystem of services. As part of any open
source evaluation, an enterprise needs to understand those services
and how they meet company IT needs.
It's no different with open source software. In this case, the
services may come from commercial open source providers, from the
community at large, or from other service providers. Whichever option
you choose, you should evaluate the following key criteria:
* Are certified versions and updates available from a trusted source?
* How viable is the community? Structure? Size? Longevity? Activity?
* What type of license does it use? What are the restrictions?
What are the licenses associated with the project and with other open
source products it depends on?
* Is commercial-grade support available? What is the quality and
responsiveness of support from the community?
* Is indemnification available? Have there been any IP actions?
* Does the product have the functionality needed?
* Does the product meet my technical requirements? Is the product
available on the platforms I need?
* What other open source products are bundled in? What products
does it depend on?
* What is the complexity of configuring and integrating this
product with other components?
* How will I manage the stream of security patches, bug fixes, and
other updates?
* What is the ROI for this product?>>
You can read this at: http://soa.sys-con.com/read/368028.htm
It would be interesting to read of your experiences with these and other OS
products in a SOA environment.
Gervas
