the TechShop http://www.techshop.ws
uses either Corel Draw or Adobe Illustrator. I have Corel. I made the design and then used drop box to send it to myself at the TechShop. The advantage of Drop Box is that it is a file folder - sort of like having a drive. I can access it from anything - a computer, my phone, ipad, etc. I opened it on the TechShop computer which is assigned to the laser cutter.
I sized it according to the nice flat band at the top of the glass (the rest of the glass has an angle to it and would have required adjustments in the design).