This is the full Active Object library, if you don't know which one to use, you probably want this one.
'net.java.dev.activeobjects:activeobjects:0.20'
<dependency>
<groupId>net.java.dev.activeobjects</groupId>
<artifactId>activeobjects</artifactId>
<version>0.20</version>
</dependency>
<dependency org="net.java.dev.activeobjects" name="activeobjects" rev="0.20"/>
"net.java.dev.activeobjects", "activeobjects", "0.20"