There are also options for rendering particles as pixels, crossing planes or as instanced geometry. The geometry options pops-up a new dialog box with controls over animation offset and synching as well as controls for exporting the particle motion keyframes to objects. I use the offset controls to make a procedurally animated flock of birds all flap their wings non-uniformly. Particles sometimes collide with objects in a scene and Outburst gives you lots of control over how they collide. You can even define what parts of the obstacle will affect particles with options for all faces, inside faces and outside faces.
Particles can bounce off an obstacle with controls over tangent and normals.
They can also stick to the obstacle, disappear or decay. The decay parameter is great for adding sparks as bullets strike a surface. One of the new features included in Outburst 1.5 is target obstacles. In its simplest form, target obstacles give Outburst particles a goal. There are controls for how particles accellerate and decellerate as they approach a target and how particles fill a target.