Back in 2011 I had worked with NServiceBus for a couple of years, and I was very happy about using it. I became sad though, when NSB version 2.5 was announced, because Udi had decided that NServiceBus would go away from the ultra liberal Apache V2 license, to requiring a paid license to use it in production.

I wasn’t sad because I thought that NServiceBus wasn’t worth the money. I was sad because I knew that the money aspect – just the fact that there was a money aspect – would suddenly become a barrier for me to introduce NServiceBus into future small to medium-sized projects.

I also realize that the money aspect was probably the one thing what was missing for NServiceBus to be looked at with greater seriousness by many companies worldwide, so – from a business perspective – I totally understand the move. It just didn’t fit my plans of building cool distributed stuff, made entirely from free frameworks and libraries.

Taking matters into my own hands

Therefore, on September the 11th 2011, I made the initial commit to the Rebus repository and laid the ground for what I wanted to be a kind of “lean NServiceBus little brother”, an NServiceBus stand-in that could be used in small systems until they became serious enough to warrant the license fee.

From the outset, Rebus mimicked NServiceBus’ APIs, and would even be able to read and understand NServiceBus endpoint mappings, so as to make porting systems back and forth between Rebus and NServiceBus easy.

Rebus turned out to be pretty neat though, and it didn’t take many alpha versions before money was suddenly being moved around by Rebus. And a few versions after that, Rebus would help some people control a couple of power plants. At that point, I hadn’t even had the chance to use Rebus to build something real myself, but other people were happily using it to solve their messaging problems.


Fast forward two years, and I’ve helped build several systems with Rebus, and I get to go to conferences and talk about it, and a big part of my daily work is to help my awesome colleagues at d60 build systems using messaging.

All is peace and quiet in Rebus-land, and then – BAM!1 – I get an email from Udi saying something along the lines of: “Have you considered turning to the dark side?” – where Udi invites me to become part of the NServiceBus core team…………!!

I did not see that one coming.

AND like that, I’m in a huge dilemma – because I really love working at d60, and I love my awesome colleagues, and I love the spirit that we have succeeded in building in the company – so it pains me to think that I would no longer be part of the d60 project.

On the other hand, I realize that this an immensely awesome opportunity to

  • get to work with Udi, whose work I have admired for the last 5 years, and
  • get to work with some of the most talented .NET developers on the globe to
  • help building a messaging library, full time, as my day job – a task that I apparently think is fun enough that I will do it while doing the dishes, while sitting up at wee hours, again and again at our monthly hackernights, etc.

Therefore – a tough decision, but an obvious one. So of course I accepted Udi’s invitation!

So how’s that going to happen?

Luckily, d60 have been nice enough to make an agreement that I can start working on NServiceBus right away, ramping up my efforts over the next 6 months while I ramp down my d60 activities. I will not ramp all the way down though: I’ll continue to hang out at the d60 office and help d60 make cool distributed stuff with messaging, participate in brown-bag meetings, etc. I’ll just spend most of the time working with the NServiceBus core team.

But what about Rebus?

There’s no doubt that I will concentrate my efforts on NServiceBus now.

But Rebus still exists! Noone can deny that 🙂 And Rebus has gained traction in places, in big as well as small companies that will most likely NOT readily replace it with something else, so I expect Rebus to continue to be refined and be maintained by its community for a long long time.

I’ve agreed with Asger Hallas, whose contributions to Rebus throughout the last two years have been invaluable, that he will be the new Rebus lead.

Asger has contributed with code in the form of all of Rebus’ RavenDB integration and several improvements, and he has contributed with excellent insights into the technical challenges of building a messaging library, and our lengthy discussions have brought much awesomeness to the table. I can think of no better person to continue the direction in which Rebus is heading.

I’m a Rebus user – should I be worried?

I don’t think so. If Rebus can make your endpoints communicate now, Rebus will still be able to make your endpoints communicate in the future. Rebus has never had an ambition to become bigger than it is right now, so if you’re satisfied now, chances are you’ll be satisfied tomorrow as well.

I’m still gonna be around!

Also: I’m not going away! I’ll still be around for helping out if you have trouble with using Rebus. I have just been given the opportunity to focus on helping a great team improve the most popular .NET service bus framework, which I hope will teach me a lot about messaging and hopefully turn out to be beneficial for NServiceBus as well.

So, please don’t hesitate to contact me if you have any questions regarding Rebus down the road. And in the future, I might be able to answer a few questions about NServiceBus as well 😉


Edit: If you’re interested, check out Udi’s perspective on this.

Exciting times!

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