1. Differences and similarities
Plug-ins
Differences and similarities

2. Adobe flash
The Adobe Flash Player browser plugin lets you view video and animated content in Firefox.
Flash uses the frame-based animation model, meaning its frame by frame animated. Creating an object for each frame, producing animated sequences.
Adobe flash has more sophisticated features like script, platform capability, socket programming, ect.
ActionScript is used to program Flash objects

3. Silverlight
Silverlight is based on the WPF animation model, which is time-based instead of frame-based, so you define the start and end conditions, and it figures out how to do it.
Silverlight has more limited features but some sophisticated ones are text representation, video/ audio, and media streaming.

4. Difference btw Silverlight and Adobe flash
Silverflash users don’t have to worry about matrices like adobe flash users.
Flash uses a compressed format, while Silverlight uses XAML for its description language.
Flash supports multiple video formats, while Silverlight implements the industry-standard VC-1 codec for video, and supports WMV and WMA.

5. Smartphone plug-in Pushover Action for Growl
The features of this action style include:
Choose to forward to Pushover only when your Mac is idle
Choose to forward to Pushover only when a notification has a minimum priority
Choose custom notification sounds for individual notification types s.
Define your own custom application key.