Whizlabs asked me to add my comments to this thread since Bala (bparanj) and I co-authored the OOAD exam for Whizlabs.
Bala had taken the IBM exam and made a proposal to Whizlabs to create an exam simulator. Whizlabs suggested that he could complete it faster if he had a co-author. Bala knew me from my postings on the Yahoo scea_j2ee group and generously offered me 50% of the royalties if I would assist him on the project. Bala's role was to come up with the questions and case studies on the basis of his familiarity with the IBM exam, while my role was to insure the quality of the questions and to write the explanations for the answers. Whizlabs posted my resume on their site promptly upon receiving it. I can only presume that Bala's is missing because he did not provide it.
Our collaboration went very smoothly, but I did feel Bala was overly harsh and intollerant in his communications with Whizlabs. For my part, I felt that Whizlabs was very accommodating to us as authors, and made every attempt to comply with our requests.
The entire process was not without hiccups, however. While I had no problem installing their software on Windows XP Professional, I discovered that the content was not properly imported into their exam engine. Problems included omitted periods (full stops) from many sentences, exhibits that could not be fully viewed because they were too large for the screen and did not have scroll bars, varying paragraph indentation and spacing from question to question, empty answer choices, answer choices from multiple questions appearing as the choices for one question, missing exhibits, etc. This resulted in considerable rework on my part to correct the errors and could have been avoided had Whizlabs been more specific about the format in which they were to receive the content and provided more QA oversight on their end. While having to do the rework was painful for me, Whizlabs was willing to make as many corrections as I requested so that in the end I was satisfied that we had produced a quality product.
Comments in this thread about exhorbitant price vs. reasonable royalties seem to be in conflict. Royalties are based on a percentage of the price so authors benefit from higher priced products. I have found Whizlab's author royalty percentage to be quite fair and on a par with what book publishing companies pay. Certainly, if you own an exam engine, create the content, and are willing to do the marketing, distribution and support yourself, you get to keep 100% of the sales price, but you also get to pay 100% of the expenses, not to mention the cost of your time.
Based on this one project, my experience with Whizlabs has been very positive.