Long time PHP development was time consuming. Initially most of the web development was done on whats known as Core PHP. To compete with other light weight development solutions like ruby on rails and all, PHP developers were looking for ways to speed up coding. There are a number of Integrated Development Environments (IDEs) APIs and frameworks, out there which reduces the complexity and improves quality of PHP development.
When iScripts engineering team was looking for MVC framework for our products, we reviewed many commercial frameworks like Zend, Yii, Cake PHP etc.. Finally came to the conclusion there are no single framework that captures all the combinations of products for different markets we have been working on. So finally we decided to create a new framework. We inherited a number of features from main frameworks. Some more than others. If you are a developer and you can see some inherited properties from Cake PHP. But we forked from it 3 years back.
On IDE we use netbeans for most part. But you can use any PHP IDE you are comfortable to edit the source code of any iscripts software product. But if you are not into these things, can can customize the products based on your specific market needs. You can focus on the more important things like marketing and customer acquisition for your website.