Filter Forge is – by quite a margin – the most powerful plug-in we've looked at here. That's because it's a tool for creating plug-ins, both generative texture-creation tools and effect filters.
“Filter Forge is an incredibly powerful new Photoshop Plugin. It's simply amazing. It gives you the power to create your own filters (you must run them from inside Filter Forge though) without any programming knowledge at all.”
“It's a powerful and logical way of creating effects that's relatively easy to learn by seeing how other effects are built. Creating filters from scratch is time-consuming, but for a wider user group, it's a great way to modify already-created effects.”