Roller now powers thousands of employee blogs at Sun Microsystems, where Johnson works as a staff engineer on the blogs.sun.com team. In addition, the open-source Roller platform powers thousands of internal blogs at IBM and more than 10,000 blogs at Javalobby.orgs JRoller.com community site, Sun officials said.
"Ive always been a big fan of open-source software … initially because I wanted cool things to play with," said the Raleigh, N.C.-based Johnson. "I thought it was a great way to save time and money, as well as a way to have a powerful blog server by putting a small effort into it."
Johnson also is the author of an upcoming new book titled "RSS and Atom in Action," published by Manning Publications. Johnson said the book is an innovators guide to building applications with blog and newsfeed technologies. In addition, Johnson said the book explains blog technologies, XML newsfeed formats and publishing protocols, with examples in Java and C#.
The second half of the book is a collection of RSS and Atom blog applications for things such as blogging via e-mail, creating planet-style blog aggregators and distributing files podcast-style, Johnson said. The book is scheduled for release March 24.
"A lot of the time the stuff at work just wasnt that interesting," he said. Johnson, who built the Roller core technology in 2002, said he worked for Haht Commerce (now part of GXS) and then SAS Institute in North Carolina.
After building Roller, Johnson said he wrote an article on the technology for OReilly Media that drew lots of attention. And soon thereafter, Johnson said he noticed that Roller wound up on FreeRoller.net, one of the first sites to deploy the Roller software. FreeRoller was started by Anthony Eden, who eventually turned the site over to the Javalobby. FreeRoller is now known as JRoller.com.
"By the time Sun got into employee blogging, FreeRoller had become JRoller." Johnson said. "And one day I noticed Sun was using Roller and I e-mailed Tim Bray [director of Web technologies at Sun]. Then I went to JavaOne," and shortly after that Johnson was working at Sun, he said.
And Johnson has been able to write his own job description. "Thats how it turned out," he said.
Meanwhile, last June, Sun moved the Roller project into the Apache Software Foundations incubator program, where "Roller has been doing very well in terms of community," Johnson said. "We received some major contributions from IBM." IBM contributed tagging code, he said.
However, Roller is being held up in the Apache incubator program by "some small issues," Johnson said. One issue is there are some components in Roller that are governed by the GNU LGPL (Lesser General Public Language).
"Apache wants to be pure, but we use Hibernate, which is licensed under LGPL," Johnson said. "Thats an issue. We may have to remove Hibernate or make it downloadable separately. Im hoping well get out [of the Apache incubator program] this year. But that is not affecting our progress."
Johnson also is working on the Blogapps project on Java.net, which is a set of code examples and utilities from his upcoming book and it also features a blog and wiki server that works with the samples.
"Blogapps is a set of examples from the book Im doing," Johnson said. "The goal is to introduce people to blog technologies."
The Blogapps server includes the Roller blog server, the JSPWiki wiki server, the Tomcat Web/application server and the HSQLDB relational database, Johnson said. HSQLDB is a small-footprint relational database system built in Java.
"At some point Id like to move to [Apache] Derby," Johnson said, referring to the open-source Derby database.
Johnson said Yale University is also using the Roller blog software, and North Carolina State University has chosen Roller to support campuswide student blogs.
Ever the champion of open-source software, Johnson said he spent a year and a half in Jamaica as a consultant helping to implement the GRASS (Geographic Resources Analysis Support System) GIS (Geographic Information System). The GRASS GIS software is used for geospatial data management and analysis, image processing, graphics/maps production, spatial modeling, and visualization.
Joked Johnson of his experience with GRASS: "I didnt go to Jamaica for the grass; I took the GRASS to Jamaica."