To create a Rib Cam with Alibre, follow the steps in Creating a Plate Cam with Alibre to Step 4.

1.  Activate a 2D sketch on the XY plane, select Insert From File and Browse to the csv file you saved (Name you gave the cam) BeginInside.csv.  The result will look something like this:

2.  Click Deactivate Sketch and Extrude this to the thickness desired.  Result will look something like this:

3.  Now activate a Sketch on the Front Face and Select Insert From File and select the other curve (Name you gave the cam) BeginOutside.csv  The result will look something like this:

4.  Click Deactivate Sketch and Extrude Cut the depth of the rib.  the result will look something like this:

5.  You can then add Hub, bore, etc to complete the cam. 

Also you can see the video