Blueprint PHP application?

Here’s a question… If someone comes to you and asks “How do I organise myself in PHP?”, what do you say? In particular, if they are an experienced programmer in other languages but still learning their way around PHP.

Forgetting frameworks for just a moment: in fact despite frameworks, PHP apps are still being written. The question I’m really asking is what application(s) would you point people at as an example for how to do PHP.

These days I find myself pointing people at Eventum, MySQL’s bug tracking application. There are things I personally have “issues” with in the way Eventum is written but those are really just my personal taste. What Eventum represents to me is a safe approach to building PHP applications – reasonably well organised and structured but still a working application, addressing real / common / complex use cases and demonstrably scalable. Also the toolset used to built Eventum and it’s corresponding learning curve is acceptable; other than PHP (and built-in APIs) it’s basically just Smarty, which is well documented.

Given that so many applications have been written in PHP, some extremely successful in terms of popularity, are there any applications you’d be happy to point people at for inspiration? Apps which, despite your personal tastes, you think make a good blueprint for doing PHP? (And if you’ve got the time) Why?