I am in the process of creating a custom module that among other things needs to provide a rich text memo capability.  I figured this would best be handled using the FCKEditor since it's already use in DNN.  I found the DotNetNuke.HtmlEditor.FckHtmlEditorProvider dll and used that in the Visual Studio toolbox, then upon adding an instance of that control it could not create it because of the error "Could not load file or assembly 'DotNetNuke, Version=3.3.6.41880..." etc.  Since I am using DNN 4.5.5, and already had that reference in my project, I figured this was just going the wrong way about it so I instead downloaded the full FCKEditor and added that to my project.  That got it working fine, but the performance of the page degrades more and more with each load during a session, for tasks that have nothing to do with the editor.  For example, without the FCKEditor on the page the most intensive task takes 5-6 seconds to finish, and this is constant across multiple times.  But when the editor is even on the page, the first try of that task takes the normal amount of time, but each successive time takes about 5 seconds longer than the previous one.  This persists throughout the session regardless of what I do on the website, until I close the window and open up a completely new session.

Has anyone used FCKEditor in a custom module before, or seen any problems similar to this?  I was thinking that perhaps the DotNetNuke version of it was highly customized to avoid this, but was unsure of any differences.  Is there something else that I can do to make the first attempt I had at adding it to my VS toolbox work, or are there some settings I'm missing that can make it not degrade performance so badly?

You don't need to add the FCKEditor code seperately to your project, everything is already installed as part of the core framework,

There is a custom control provided with the core to allow you to use FCKEditor in your module.

First, register the control in your ascx file:

<%@ Register Src="~/controls/texteditor.ascx" TagName="texteditor" TagPrefix="Dnn" %>

Then create an instance of the editor:

<Dnn:texteditor ID="MyTextEditor" runat="server" Width="600px" Height="500px" ChooseMode="true" />

Hope that helps.

Scratch that...didn't realize that part was only set through the host options for each instance of the module, I was able to set it up correctly using that option.