License types:

• Full license
  It allows you to use all functions of Markush Editor.
  To request a full license key, contact [email protected].

• Evaluation license
  The time-limited license offers full functionality for 3 days.
  Click here for the evaluation license or contact [email protected].

Without valid Markush Editor license you can use the desktop application for free of charge in viewer mode. In viewer mode you can open and view Markush structure files, but you can't create new structures or modify the opened structures. Please check ChemAxon License Management for additional details.