Our Indian overseas developers have written the following piece of code (C# 2.0):

public abstract class ObjectMapperBase<T> where T : new()
{
    internal abstract bool UpdateObject(T plainObjectOrginal, T plainObjectNew, WebMethod fwm, IDbTransaction transaction);                     
}

Inheritor example:

public abstract class OracleObjectMapperBase<T> : ObjectMapperBase<T> where T : new()
{
    internal override bool UpdateObject(T plainObjectOrginal,
                                     T plainObjectNew,
                                     WebMethod fwm,
                                     IDbTransaction transaction)
    {
       //Fancy Reflection code
    }
}

I've never seen the where keyword before after the class name. What does this do?