My intention to learn some new tricks has been going quite well.
I've been working with PHP on a little project of mine. It's a system monitoring application - data about the health of systems is inserted into a database and reports displayed on a web page.
It was written using JSP, and that works extremely well up to a point. But it doesn't really need any specific technology - there's nothing in JSP that is especially suited to the task, which is fairly simple. Rewriting it in PHP therefore looked fairly easy, and having a real project is a good way to learn something new.
And it worked very well. PHP is very easy to develop in, and I was able to implement some new features as well.
So how would I compare PHP and JSP? Each has advantages and disadvantages:
PHP is quicker to get going in, so putting together simple prototypes and building on them is slightly easier.
I found it easier to make silly mistakes in PHP - the language is a bit more forgiving, so that some typos that would have generated a failure in JSP get through and you end up with something that doesn't quite work right. You need to impose a bit more discipline with PHP.
PHP doesn't need a huge java process to run a servlet engine. This has always bothered me - the overhead of a servlet container, just to dynamically create a few web pages, is considerable.
The really big advantage of PHP, though, is that it's very easy to create images on the fly. The GD extension is pretty well standard, and works (although not capable of horizontal dashed line - doh!). I've tried various ways of creating graphs using JSP and, while it's possible, it's neither easy nor pleasant. There's clearly for an opening here for a dead-easy JSP image generator to be created (or, if it exists, to come out from wherever it's been hiding).
The downside to PHP was the length of time it took to put the stack together. Tomcat is a zip file you unzip, and you're basically done. PHP makes the common mistake of using autotools and is a right pain in the neck to configure and build correctly as a result. (Note that its not PHP's fault; it's autoconf.)
So that project is almost done, and while I wouldn't claim to be fluent in PHP, at least I'm capable of asking directions in the language. Now on to ruby on rails when I get some more free time...