9 min read

What is Railo?

Railo is an open source Java application server that implements CFML (ColdFusion Markup Language), a tag based language from Adobe’s commercial product “ColdFusion.” Its performance is excellent, and it includes features that significantly increase productivity.

Railo is a relative newcomer, but has been making some impressive ripples in the industry lately. This article is a primer on some of the critical advantages of Railo and why it is worth a serious look for web application development.

Isn’t ColdFusion dead?

A few years back, an article was published naming 10 technologies that were dead or dying, and to many people’s surprise, ColdFusion was in that list. That caused a lot of waves. One thing about CFML developers – they are passionate about their programming language!

ColdFusion has seen moderate success in specific vertical markets, but has been notably well accepted by the US Government. In comparison to dominant development languages, CFML never seemed to find real favor with the masses. Since ColdFusion was re-engineered to run entirely on Java, and with the arrival of Adobe Flex a few years ago which integrates Flash and ColdFusion, this has changed quite a bit. Adobe’s ColdFusion product integrates so well with Flex that it has spawned new interest.

One of the largest complaints about Adobe ColdFusion has always been the price. It’s been my experience that CFML developers consider themselves to be industry peers of LAMP ( Linux, Apache, MySQL, PHP) developers, who use all open source tools. The majority of LAMP developers consider their skills much higher than that of CFML developers. This has only fed the fury over the years of CFML developers who claim that the investment in purchasing ColdFusion is a quick return on investment since CFML is so much more productive.

Now along comes Railo, offering a free and open source solution to the CFML developers’ dreams. Not only is it free, but also it performs fantastic, is stable, and is updated reasonably frequently. This is good news for CFML, which is, in my opinion, highly underrated, mostly due to poor marketing and sales price points over the years. CFML is actually quite a powerful and surprisingly productive language, and was designed to be a RAD (Rapid Application Development) tool. It has grown into a significantly better product, and certainly does deserve more respect than it has had. But enough about CFML, let’s talk about why I find Railo is so impressive and what distinguishes itself from the competition.

What can you do with Railo?

Perhaps the best way to answer this is to say, “What CAN’T you do with Railo?” The CFML language is essentially a big java tag library. CFML has grown into an impressive library over the years and Railo supports everything that Adobe’s product supports that is in mainstream use. (There is some difference between the support as both Railo and Adobe release new versions of their products).

The core features of Railo’s language provide easy to learn tags for everything from database queries to sending dynamic email messages to scripting connections with ftp and Amazon s3 storage. Pretty much anything you can do with PHP you can do with Railo. Here’s the catch – generally speaking, it takes less time to implement a solution using CFML than it does with PHP, ASP.net or pure Java.

Use CFML for the basics; Extend using Java.

While Railo gives you a LOT of built in functions, the real truth of the situation is that it is Java under the hood. All the tags and functions ultimately get compiled and run as Java byte code. The language is well designed, however, so that you can mix and match your CFML and Java code.

For instance, if you wanted to read in a text file, you can use the built in tag CFFILE:

This reads in the contents of the text file, and stores it in the specified variable.

To display that content in the web browser, you would output it like so:


To illustrate how Java can be used directly in your code, this same task can be done using Java objects instead of the built in CFML tags like so:


These two small pieces of code achieve the same goals. My point is that the CFML language isn’t limited to just CFML, you can instantiate and use any Java object anywhere within your code.

This makes the language incredibly flexible, since you can use the CFML tags for quick and easy tasks, and use Java for heavy lifting where needed.

Deployment and Development Environments

All versions of Railo can be downloaded either as an “express,” “server” or “custom” deployment. The express edition is extremely easy for developers to get up and running and usually involves just decompressing a zip file onto your local system and starting it up. The server package comes along with Caucho Resin, a very high performance java application server. (Side note – some of the tools included with Resin are pretty impressive as well, including their all-java implementation of PHP!). The custom deployment package is for launching Railo on other Java servlet containers like Tomcat or Weblogic.

Setting up Railo on a production server wasn’t difficult, granted it is a bit more involved than installing RPMs of your favorite PHP version, but documentation was easily found on Railo’s site and other sites found through Google.

Like Adobe’s product, Railo comes with web administration tools to manage the server and application-specific settings and resources. This is a big step up from the PHP and Linux world, where you normally need to configure a lot of your application’s settings (data sources for example) in configuration files. The Railo administrator goes a few steps beyond Adobe as well, and makes context specific administration consoles available, so individual applications and websites can define their own sandboxed data sources, virtual mappings, and more. This is a really nice touch, and has been a requested feature for a long time.

Where Railo Shines

I have already reviewed some of the reasons why Railo is impressive. Aside from being a very powerful RAD, with performance that rivals or beats Adobe, Railo distinguishes itself further with some impressive features.

Virtual File systems and Mappings

As developers, we have all had to deal with managing remote or compressed files at one time or another. This feature in Railo does in a few mouse clicks what takes hundreds of lines of code. Railo lets you map remote file systems, like FTP, drive shares, and even Amazon S3 buckets and assign them to a virtual path in your application! This means that you can use the simple built in functions for file manipulation, and treat those files as if they were sitting right on the local file system. The support goes even further, and lets you map Java jar files and .zip files, so you can dynamically reference and run code sitting inside compressed archives.

Setting up new mappings is a point-and-click affair in the Railo administrator or can be done programmatically.

Application Distribution and Source Code Security

The Java world has always been a step (alright, several steps) ahead of web application developers in packaging and distribution of applications. Many developers have their own home-grown methods for deploying a site and many web development applications, like Dreamweaver, have an FTP based method of deployment. Ultimately, it usually means handing over unprotected source code.

CFML development has been the same way (yes, Adobe did have a way to compile .cfm templates, but my research shows it is both clumsy to use and not very popular). Railo brings “Java world” package deployment to CFML development. You can compile a whole application to Java byte code, compress it to a jar file and deploy it on any other Railo server. Railo is even smart enough to let you map a remote jar file on an FTP site and run it as a local web application. This means you have all the tools you need to deploy web applications and not expose your source.

Built in AMF Support for Flex/Flash Applications

Since Adobe open-sourced their BlazeDS AMF tools, Railo has integrated them making an easy to use system that “just works” with Flash applications.

Inter-Application Integration, PDF and Video Manipulation

CFML already has great capability for integrating with a huge number of database systems and can be expanded to use any of the huge number of open source Java projects.

Railo can be used to talk to Amazon Web Services, like EC2 and S3 for cloud computing applications. Railo also has built in features for file conversions, such as dynamically generating PDFs, and programmatic editing and format conversions of digital video. A few simple lines of code can convert your video files to different formats, extract thumbnails for web previews, and then you could have them dropped on Amazon S3 to be served from the cloud. Very cool stuff, and worth looking at some of the examples on the Railo website.

As you look over code that uses these features, it looks quite simple and it is amazing that Railo makes them look like child’s play, but there is serious inter-system integration going on behind the scenes. Railo makes it so very easy to add these capabilities to any web application.

Infinitely Expandable with Java

As mentioned above, it is easy to invoke Java classes from within CFML pages. Since Railo itself runs in a Java container, that means that any classes or code from the Java world can be integrated and used with a Railo application.

My Experience Building a Railo Project

My company has used ColdFusion for several projects. One of our commercial products is built on it and was originally designed for Adobe ColdFusion. Our product does a lot of heavy lifting with databases, internationalization, document format conversions, PDF previews and a lot more.

Early in 2009 we did a complete conversion of the source to be compatible with Railo. There were only minor areas where our code needed to change, and most of them were with custom Java code that we wrote that simply needed updated to compatible with Railo’s Java libraries. The pleasant surprise came when we were done and noticed a significant performance increase running on Railo.


In summary, I have been very impressed with Railo. It is community-driven; the people at Railo are responsive and truly care about the developer community, and the product really delivers what it claims. They have provided an application development platform that is both industry compatible and innovative. I think all seasoned web application developers will be able to appreciate what Railo has to offer. I believe that such powerful integration done so easily with only a few lines of code will draw a lot of attention. This is definitely a technology you should keep an eye on.

Subscribe to the weekly Packt Hub newsletter. We'll send you the results of our AI Now Survey, featuring data and insights from across the tech landscape.


Please enter your comment!
Please enter your name here