<p>I have an oc4j installation bereft of any release notes or version documentation. In the absence of such documents, how do I know for sure, which version of oc4j I am using?</p>

Check Server header in HTTP headers. For example with wget or curl;
```
```
wget -S <url-to-server>
curl -I <url-to-server>
```
```
or with browser, which can show HTTP headers.
There should be a header something like
```
```
Server: Oracle-Application-Server-10g/10.1.3.1.0 Oracle-HTTP-Server
```
```