A virgule is also known as a “forward slash,” although a “backslash” would fall under the same definition.
In technical writing, it is used to distinguish between two choices as a replacement for a hyphen, between “and” and “or” to signify one or both is a possibility, or two show that a certain object is composed of two seperate objects:
One would want to use a SCSI/Firewire cord.
With this order, you get sausage and/or toast.
Have you tried making music with Max/MSP?
In more proper writing one would replace the above with these:
One would use a SCSI or Firewire cord.
With this order, you get sausage, toast, or both.
(Max/MSP is a brandname and isn't changed)
The only time one uses a virgule in proper writing is as a line break for poetry that appears within prose:
The turkey shot out of the oven / And rocketed into the air.