@Encode, your suggestion is what I have tried and would expect, but I get different behaviour: MapleTA automatically XML decodes the input (unexpected behaviour) and then saves the decodes.

For example, I would like to have MapleTA show this as plain text:

What is the result of the following markup:
<img>http://www.example.com/example.jpg</img>

Because it contains xml, I have to encode it to:

But when I click "finish" to save the question, and go to "edit" again, MaplteTA will show that it has been stored as this:

So MaplteTA modifies my plain "source" input question text by automatically xml encoding the source input text.

Even when I don't click on "edit" to show what it has stored, but go to the question in an assigment immediately, it will render the question that is modified by MapleTA:

The solution to this problem would be to let MaplteTA not xml encode question text on the serverside.

@Encode, your suggestion is what I have tried and would expect, but I get different behaviour: MapleTA automatically XML decodes the input (unexpected behaviour) and then saves the decodes.

For example, I would like to have MapleTA show this as plain text:

What is the result of the following markup:
<img>http://www.example.com/example.jpg</img>

Because it contains xml, I have to encode it to:

But when I click "finish" to save the question, and go to "edit" again, MaplteTA will show that it has been stored as this:

So MaplteTA modifies my plain "source" input question text by automatically xml encoding the source input text.

Even when I don't click on "edit" to show what it has stored, but go to the question in an assigment immediately, it will render the question that is modified by MapleTA:

The solution to this problem would be to let MaplteTA not xml encode question text on the serverside.