An executory contract is a contract under which one or more parties has not yet performed. A non-executory contract is one which has been performed already. For example: Abel orally has agreed to buy Baker's land, and Baker's attorney has drafted a contract. At this stage it is executory because neither Abel nor Baker has signed it.
In bankruptcy law, an executory contract is a contract between a debtor and another party under which both sides still have important performance remaining. Examples of executory contracts are real estate leases, equipment leases, development contracts and licenses to intellectual property.