In other words, the free part is the core IDE plus a few features; the commercial edition adds a lot of value for most users.
CEO Sergey Dimitriev remarks:
Open source has become the mainstream, and we continue to embrace it as an exciting challenge. In brief, we’re not changing direction — we’re moving forward.
IDEA is an excellent and popular IDE and last time I looked I found it more productive and enjoyable to use than its obvious alternative, Eclipse. I imagine that IntelliJ is hoping to strengthen the community and availability of add-ons for IDEA, as well as attracting new users.
Although this is welcome news – and I’d encourage any Java developer to try the product – it would be interesting to know more about why JebBrains is taking this step. Borland’s JBuilder was once highly successful, until the free Eclipse offering eroded its market share. Seeing how important the add-on community was in Eclipse, Borland belatedly issued a free JBuilder and sought to make it an alternative IDE platform for third parties, but by then it was too late. JBuilder was discontinued and a new product of the same name appeared in its place, built on Eclipse; it is still available but is now a niche product. I’ve not got any up-to-date figures but I’d expect JBuilder’s market share to be tiny now.
Unlike JBuilder, IDEA has remained popular despite Eclipse. Comments on stackoverflow, for example, show how well liked it is:
Eclipse was the first IDE to move me off of XEmacs. However, when my employer offered to buy me a Intellij IDEA license if I wanted one it only took 3 days with an evaluation copy to convince me to go for it.
It seems like so many small things are just nicer.
The problem is that the free Eclipse, or free NetBeans, or free Oracle JDeveloper, are good enough to get your work done, making it hard to compete; and I am not sure whether the addition of free IntelliJ IDEA to the list is a sign of strength or weakness.
My guess is that serious users will still want the commercial edition with its many additional features, so this may not be as radical a step as it first appears.