Measuring from the first Subversion commit, Solar was 6 years old on 14 Feb 2011. The project has come a long way since then, and has evolved from a collection of library classes with some content domain models, to a general purpose framework.

Moore’s Law tells us computer power doubles about every 18 months; it’s how we measure generations for computers. 6 years is 4 generations, which makes Solar the equivalent of an 80 to 100 year old person. Just like with a mature person, there is a great deal of knowledge and craft embedded in Solar, but it also still shows its roots and carries the weight of decisions from early in its life.

With all that in mind, it’s time to start working on Solar version two, using the formal namespaces and other features of PHP 5.3. There are some other very significant changes on the way as well.

The first change is the name of the project. Even though Solar (the PHP 5 framework) came first, the name is too easy to confuse with Apache Solr (the search system). So, after some discussion with others, Solar v2 will be called Aura.

The second change is in the fundamental organization of the project. Solar became a full-stack framework very quickly, with all classes descending from a base class, and using and a service locator to manage dependencies. By comparison, Aura is a collection of independent library packages; it uses no base classes, and is oriented toward a dependency injection container proper to manage dependencies. Aura also has an additional “system” package that assembles those libraries into a cohesive framework (the way Solar is now). That way, those who want to use only one or two Aura packages can do so, and developers who want a full framework can also get what they need.

There are lots of other significant changes, and I expect I’ll write about those in the future. Until then, if the project sounds interesting, you can find the Github repos at Aura also has a mailing list at, and you can join the IRC room on Freenode at #auraphp.

Meanwhile, Solar will keep getting as much love and attention as it has over the past year or so. But I do expect, eventually, that we will be able to extract all the best Solar behaviors to Aura. Solar won’t ever really go away (software projects almost never do), but I expect it will be eclipsed by Aura at some point in the future.

You can see what Aura looks like by examining the various Aura packages already in place:

  • Aura.Autoload, an autoloader package
  • Aura.Di, a dependency injection container,
  • Aura.Router, a web routing system,
  • Aura.Signal, a signal slots / event handler implementation,
  • Aura.Cli, a collection of command-line tools, and
  • the system package that provides a framework around the libraries

Take a look around; I hope PHP 5.3+ developers who want independent library packages will like what they see.

Are you stuck with a legacy PHP application? You should buy my book because it gives you a step-by-step guide to improving you codebase, all while keeping it running the whole time.