Many distance learning courseware packages include a whiteboard tool. The purpose of an electronic whiteboard is the same as that of a blackboard or whiteboard in a school. Instructors and students write or draw on the board in order to share their ideas and to deliver instruction. Electronic whiteboards work as graphical chat tools. They allow multiple users to draw, paint, and share existing graphical files in real time. Unfortunately, exclusively graphical workspace is not accessible to users of screen readers. Even the text tools that are available in these environments often produce text in a way that cannot be accessed by screen readers.
Current whiteboard tools also include many exclusively mouse-driven functions, which exclude people who cannot use a mouse. As result of these limitations, students and instructors with certain disabilities cannot participate actively in whiteboard activities, either because they are unable to use the graphical tools or because they are unable to see the shared environment. This is very similar to experiences of some individuals with disabilities in regular classrooms.
If an instructor feels that using a whiteboard tool is essential to his or her course, participants can use the same strategies used in the regular classroom to increase accessibility. They will need to consistently and meaningfully narrate what is being drawn or typed on the whiteboard. This requires considerable skill and discipline on the part of all participants. Distributing the information before the whiteboard session in accessible format will make it easier for students with disabilities—and often also for nondisabled students who need more time to engage with the material—to participate. At this time, the best way to accommodate users of screen readers and other assistive technology is to avoid using whiteboard tools for delivering content that is essential and significant.
For more information on distance learning courseware packages, see the AccessIT Knowledge Base article How do courseware products differ on accessibility? 
-  How do courseware products differ on accessibility?