A few hours ago, we pushed Expressive 1.0.

This is a huge milestone for the ZF3 initiative; I've even called it the cornerstone. It signals a huge shift in direction for the project, returning to its roots as a component library. Expressive itself, however, also signals the future of PHP applications we envision: composed of layered, single-purpose PSR-7 middleware.

I won't go into the details of the Expressive 1.0 release; you can read about it on the Zend Framework blog.

What I'm excited about is that this marks the fruition of the PSR-7 effort for me. I started work on PSR-7 due to the successes I'd had working with middleware in node.js, and wanted to see a similar ecosystem in PHP.

Today, we have:

• Relay
• Slim (v3)
• Penny
• Expressive

and likely a number of others. The ecosystem has blossomed tremendously already; just take a look at the PSR-7 packages on Packagist! Chances are, if you need to accomplish something via middleware, somebody has already written it; if they haven't you can likely write it in a handful of lines of code.

Expressive started out with me remarking off-handedly that I'd like to create a project that is to Stratigility (the ZF PSR-7 middleware foundation) what Express is to Connect — in other words, a microframework providing the most often-desired features when writing web applications and APIs, but no more. What I saw with Connect and Express was that developers were able to write single-purpose middleware, share it, and layer middleware to create complex applications. The features Express layered on top of Connect simplified the most common problems of routing middleware, while Connect provided a robust, simple runtime.

Enrico was particularly excited about the concept, and got the ball rolling last summer, and it's been a whirlwind of activity ever since. And then others started playing with the code, and contributing ideas, validating the approach, and suggesting new directions. We now have a microframework in place that rivals zend-mvc in flexibility, while retaining our core principals of simplicity and minimalism.

How do I know the approach works? This site runs on Expressive already. And many of our users and contributors are already running on it. But the best validation I've read was from one of our prolific Zend Framework contributors, Michaël Gallego, on a recent thread:

For me the only reason to use Zend\Mvc (and, therefore, the eco-system around it) is the facilities provided by the module eco-systems. But even in that case, I've found out that for that, the middleware philosophy makes it so much easier. You no longer need to install Zend\Authentication that would try to map into the mvc, spending a lot of time how it works… Want an authentication? Just analyze your need, and boom, ten lines letter, it's done.

That sort of comment and realization was exactly what I experienced working in node.js almost two years ago. And now, today, it's a reality in PHP.