Railo:
Railo was created by the Swiss company Railo Technologies GmbH, intended as a high performance alternative to Adobe ColdFusion. 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. Put simply, it is an application that reads and interprets (parses) CFML (.cfml, .cfm, .cfc) files and executes the given (scripted) commands (instructions) on the go.
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.
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. The custom deployment package is for launching Railo on other Java servlet containers like Tomcat or Weblogic.
Like Adobes product, Railo comes with web administration tools to manage the server and application-specific settings and resources.
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.