The mxj object has been tested in both Max 4 and Max 5, although 5 is preferred

If you are going to be working with the source code then make sure you have your development environment setup (an example of setting up eclipse is here ), otherwise download the supporting 'Max OSC Java' files from the Files page. 

To add the mxj object you will need to edit the Max java config in your Max install :

Max 5.0\Cycling '74\java\max.java.config.txt

Development Setup 

For the development setup you will want to add something like this :

max.dynamic.class.dir C:/dev/workspace/OSCLib/bin
max.dynamic.class.dir C:/dev/workspace/MAX-OSCLib/bin

max.dynamic.jar.dir C:/dev/lib/java

where 'C:/dev/workspace' is the path of my Eclipse workspace and C:/dev/lib/java is where I keep my .jar files (mina, log4j etc..)

Normal Setup 

For a non-development setup add a dynamic class setting to point to where you unpacked the java class files, e.g.

max.dynamic.class.dir C:/stuff/Max-OSC-java/java/classes

and a dynamic jar setting for the jar files :

max.dynamic.jar.dir C:/stuff/Max-OSC-java/java/lib

alternatively you can copy the files directly into the Max application folders Max 5.0\Cycling '74\java\lib and Max 5.0\Cycling '74\java\classes.

Then to use the OSC HTTP server add a new mxj object :

mxj com.relivethefuture.osc.OSCHTTP

and to add a server on port 4444 send a message :

addServer 4444

after which the output window should say 'server is listening at port 4444'