Android programming question - fork/exec in Android?

Is there a standard native Android content provider that will return data listing all of the apps currently installed on the cellphone. Something like open()/readdir() on a Linux bin directory.

Given that you know an app is installed on an Android cellphone, and you know that apps name, how do you la开发者_StackOverflowunch that app from a completely different and unrelated app. You might not know which Intents/Broadcasts/URIs the app you want to launch is listening for. And not all Android apps are written to respond to Intent/URI broadcasts or requests....

The idea is that you don't care what apps are on the phone, you only care about what intents they are listening for. If you need to browse for a file what does it matter which file browser the person has installed? All you need to do is tell the OS that you want to pick a file and let the OS handle that.