The easiest way to start K2 processes is by using a K2 SmartForm as a 'plan' page to start a process instance. You would create this SmartForm using Visual Studio, and you do not need any additional code to be able to start process instances.

You may also reference the K2ROM assembly from a normal ASP.NET or Windows application, and use the methods exposed by the K2ROM to start process instances.

There are many different options when it comes to starting process instances (for example, message queue listeners, web services, windows applications), but they would all normally reference the K2ROM.dll in some way.

For more information and walkthroughs, I would recommend downloading the training material available from the K2 Partner and Customer portal site:
http://portal.k2workflow.com

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