In the generic sense, the thing that (IMO) makes perl a ground breaking langauge it that it tries to support most of the facilities available on it's original target platform, whilst reducing the complexity (and typing) involved in using them; especially the most commonly used of those facilties.

To achieve this, required avoiding the dogma's of purity, orthogonality and elegance. The vision to avoid the NIH syndrome by adopting and adapting useful facilities, features and idioms from other langauges, platforms and cultures and making them it's own.

The resulting, slightly messy, slightly confusing, somewhat inelegant, often terse language structure owes it's syntax to the premise that doing frequently used constructs should be quick to write and quick to process. Less frequently used constructs often requiring more syntax & requiring more effort. Often called the Huffman principle.

By eshewing the need to stick to any rigid overarching design principles, in favour doing what works, means that you get a language that depite having more than a few inconsistances and rough edges, is far and away the most productive langauge for those that can adapt to it's foibles.

My great hope is that the next version will look beyond the focus of it's original platform and show the same willingness to adopt and adapt from the wider circle of platforms and languages whilst retaining the balance between functionality and usability.