@mherrmann - There are various ways you could monetize Helium and be open source - here are a few ideas. All of them assume that you will be open sourcing your code. The reason for open sourcing this would be to basically achieve wider adoption which will in turn allow you to monetize 5-10% of your audience (Enterprise customer for example).

1. Open Core Licensing - You could create a community edition and an enterprise edition. The community edition would be completely open source and available for free. While you work on the community edition you could identify the 5% of additional features that certain customers (Enterprise for example) would pay for. I think this is a pretty fair way to balance between giving away a free product and creating an enterprise/professional edition where you'd charge a license fee from customers who would have the ability to pay for it. One of the challenges with this model is to make sure you find the right balance between the community and enterprise edition since some people will be upset that certain feature aren't released in the community but make it into the enterprise edition.

2. SaaS - If you open source it and gain widespread adoption - at some point it might makes sense to create a service that allow users to run these tests on the cloud and create a complete suite of features around it. Many developers are happy to pay a service fee for using an hosted version of the open source software that allow them to not deal with hosting, patching and servicing that software. If you do that releasing it under the AGPL will give you a competitive advantage since if someone would like to create a hosted service and improve the open source software, they would have to release all changes to the community (or license a commercial version from you), however if you decide to add some secret sauce in the hosted solution, you ARE NOT required to release it to the community since you could license it under a commercial license to yourself.

3. Offer professional services, support and training - Once developers will start using this in their workflow and start being dependent on that software, they will want the peace of mind of paying for support (or the ability to contact you and ask questions). You could have various SLA of support. For examples: Community edition (FREE) would have access to community forum where users could help each other - at first you'd seed that forum with your own support to kickstart the community. Then you could offer several level of support, from email (9-5 or 24/7) to phone support to various customers. Additionally you could offer up to a certain amount of training or consulting to write custom tests for customers who will need your help integrating this into their workflow. Most often people will opt for paying for a basic license even if the software is free just so they have someone to nag and talk to if things go south.

There are more ways that you could monetize open source - if you found this reply useful and would like to learn more - feel free to reach out to adam (at) binpress (dot) com - I am the co-founder at http://www.binpress.com - the marketplace for commercial open source - we're on a mission to help developers monetize their open source projects.