The Advanced PHP Cache is a PHP extension which primarily serves as an opcode cache for PHP. The basic idea is to save PHP from re-evaluating the PHP code to intermediate bytecode on each request. Installing and enabling APC already yields a significant performance benefit. However, APC is not a black box that will magically change all for the better. More over it is important to understand that APC needs memory to operate.
Apostle provides a nifty facility for sending app-generated, transactional emails from your application including Wordpress-like mail formatting and full tracking (delivery, opening, clicking etc.) of all emails sent. No need to set up email facilities on your app server!
Most applications will have one or two sidebars and often you want to control the content that should appear in the sidebar based on the action. For example you will want to show something different on the homepage as opposed to some view page. While achieving this you generally also want to avoid putting the layout into each view, as that would mean if you wanted to change the layout (e.g. put the sidebar on the left instead of the right or do some funky layout which requires an additional div tag to be added) you'd have to go through every view, which does not achieve good code re-use. It is also bad practice to have lots of if statements in column2 layout just so that you can generate the sidebar correctly.
Let's say our table 'mug' has a column named 'color' of the type ENUM('red','green','blue').
We want to replace the textfield for the attribute color in the create and update forms of a 'mug' with a drop down list, which has the enum values as options.
The main code was contributed by zaccaria in the forum (see this post).