From time to time you get new users on the Tapestry mailing list asking people to compare Tapestry to some other frameworks. While sometimes these discussions degenerate to the level of "my framework is best", Alex Kotchnev, Tynamo.org's very own JDO guy, provides this level-headed and well reasoned reply:
In the past five years, I worked on a number of greenfield projects. In three out of four, we ended up choosing Grails - it is very hard to deny the market & mindshare , the expansive documentation, the big name company behind the project, the large community, a massive number of plugins (for pretty much anything that you'd want), the end-to-end stack (so, you don't have to choose your ORM, DI, etc) and the ease of getting started with a Grails project.
However, after working on a couple of these Grails projects for a few years, the latest project I got involved with , I chose Tapestry. In some cases, I've missed some of the niceties that Grails brings out of the box, but without too much effort I've been able to replicate them fairly easily.
The biggest reasons for picking Tapestry over Grails on this latest project have been:
On the first issue, if you will be using Groovy for your pages, you will be in the same boat as Grails. Personally, I wouldn't recommend it - Tapestry already pushes the envelope on Java quite a bit, so your Java code ends up being very short and sweet already. In the past, I had attempted to use Scala in a tapestry app, and ended up having to just deal w/ some of the mismatches between the language and the framework and my pages ended up looking up like the same old java pages I would have had but with a different syntax.
On the second issue, there is the grails resources plugin that tries to pull resources kinda like Tapestry, but using it requires this artificial separation into resource bundles which seems to be a PITA and somewhat mind bending.
On the abundance of Grails plugins - after using a bunch for the projects I was working on, it turned out that many were not well maintained so we hadto take over and maintain them ourselves. Sometimes, they're a good starting point, but in the end ended up less of a factor than I initially thought.
I originally very much enjoyed the Grails build system (running on top of Gradle); however, with a pretty simple project setup, Maven seems to bejust as straightforward. If you wanted Gradle, you could use that for your Tapestry app, and be on-par w/ Grails.
On the latest project that I chose Tapestry for , I have been very happy with my choice. On a few occasions I've run into some frustrations (e.g. for rendering emails, I ended up having to use Freemarker, whereas with Grails the template rendering for emails comes for 'free' ; I had to build my own equivalent of the Grails "console" plugin where you can run Groovy commands inside of your running application); however, in all cases, the solution has turned out to be more elegant than I had expected (albeit, it required deeper tweaks in the framework than I had expected).