<p>When we write in a Javascript expression : </p>

<pre><code>expression &lt; &lt;%=variableJsp%&gt; 
</code></pre>

<p>the double "&lt;" seems to be a problem and the JSP is not interpreted ?</p>

<p>Is it a fault of the other servers that should not accept this type of expression ? Or WebSphere that bugs ?</p>

I find it generally a bad idea to inline javascript on jsp pages.Your problem is only one of the reasons to make javascript functions external.
Although I do not know websphere, this has happened to me on other containers.
If you insist on keeping it inline, you can probably use
```
```
expression &lt; <%=variableJsp%>
```
```