As far as I know there isn't a Maven plugin for either Apache Daemon or Akuma. Though you could attempt to invoke them from within a Maven build by using the maven-exec-plugin.
As far as your companies reservations about using GPL-licensed products, it's worth reading up on the implications of use. It is not as virulent as corporations fear. Here's an interpretation of the GPL. It of course doesn't carry any weight in law (and may not be correct or supported by precedent, I am not a lawyer), but might be sufficient to allow you to start a conversation with your legal people.
From the referenced page:
Simply combining a copyrighted work with another work does not create a derivative work. The original copyrighted work must be modified in some way. The resulting derivative work must itself "represent an original work of authorship." So if the licensee does not modify the original GPL-licensed program, but merely runs it, he is not creating a derivative work.
There is the Appassembler Maven plugin that I think does what you need (though it does create JSW wrappers). It creates a shell script (and a bat file), and collects all the application jars into a directory. It can optionally be configured to create JSW-based Daemon configurations.
Here is an example configuration that will generate the standalone application in the target/appassembler folder, and generate the JSW wrapper files in the target/appassembler/jsw/myApp directory. Note the assemble goal is bound to the integration-test phase to ensure the project's jar is created. To generate the output run mvn verify or to just generate the service wrappers run mvn package:
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>appassembler-maven-plugin</artifactId>
<version>1.0</version>
<executions>
<execution>
<id>assemble-standalone</id>
<phase>integration-test</phase>
<goals>
<goal>assemble</goal>
</goals>
<configuration>
<programs>
<program>
<mainClass>name.seller.rich.MyMainClass</mainClass>
<name>myShellScript</name>
</program>
</programs>
<platforms>
<platform>windows</platform>
<platform>unix</platform>
</platforms>
<!--collect all jars into the lib directory-->
<repositoryLayout>flat</repositoryLayout>
<repositoryName>lib</repositoryName>
</configuration>
</execution>
<execution>
<id>generate-jsw-scripts</id>
<phase>package</phase>
<goals>
<goal>generate-daemons</goal>
</goals>
<configuration>
<!--declare the JSW config -->
<daemons>
<daemon>
<id>myApp</id>
<mainClass>name.seller.rich.MyMainClass</mainClass>
<commandLineArguments>
<commandLineArgument>start</commandLineArgument>
</commandLineArguments>
<platforms>
<platform>jsw</platform>
</platforms>
</daemon>
</daemons>
<target>${project.build.directory}/appassembler</target>
</configuration>
</execution>
</executions>
</plugin>
For reference the generated files are as follows:
myApp\bin\myApp
myApp\bin\myApp.bat
myApp\bin\wrapper-linux-x86-32
myApp\bin\wrapper-macosx-universal-32
myApp\bin\wrapper-solaris-x86-32
myApp\bin\wrapper-windows-x86-32.exe
myApp\conf\wrapper.conf
myApp\lib\libwrapper-linux-x86-32.so
myApp\lib\libwrapper-macosx-universal-32.jnilib
myApp\lib\libwrapper-solaris-x86-32.so
myApp\lib\wrapper-windows-x86-32.dll
myApp\lib\wrapper.jar
