To create a Groove cam with Alibre, do all the steps in Creating a Plate Cam with Alibre, down to the step 4.

1.Activate a Sketch in a Plane (XY).

2.Draw a Circle that is large enough to have material outside the groove. and Extrude the circle thick enough for the groove.  See below:

3.Activate a sketch on the face of the cylinder created. 

4.Go to Insert From File and Browse to the two files you saved.  One will be Name BeginInside.csv and the other will be Name BeginOutside.csv. where Name is the name you gave the cam.  the two curves will look something like this:

 

5.Click Deactivate Sketch and select Extrude Cut and enter the depth of the groove.  The resulting cam will look something like this:

 

 

6.A rib cam can be created in a similar fashion, except instead of an Extrude cut, an Extrude feature will be created for the rib.

There is also a video for how this is done.