You know, there aren’t many people whose communication style, approach, and contribution history earn my confidence so completely. I can probably count on two hands the people I hold in that regard in this industry. Mario and Armin are two of them. It’s incredibly hard to build trust online these days, but there’s something about this Viennese crew that I like.
This was a solid letter to the fans. I get why it’s disappointing to some, but it sounds like it was the right move for them personally. For people who’ve earned that kind of credibility, I say congrats on the move.
Pi is a coding agent harness, like Claude Code, but significantly better and more elegant. Here is a good post describing it: https://lucumr.pocoo.org/2026/1/31/pi/
I switched a few months ago and have not looked back. Unfortunately Anthropic blocked access from Claude Subscription users today, but that's a different story.
I think it has something to do with a core library that is or was used in one of the other AI-related tools that got some buzz recently.
I'm not sure if this library or if the AI tool itself really matter all that much, but a lot of people seem to think that they do, or will anyways, which is probably why this post has no context. Because the author assumes that both the library and the tool are well known, but I think they're only well known by those in the AI world.
You know how it is. You only know what you know, and it's hard to remember what it was like when you didn't know. When you're around people who talk about the same things all the time, it's easy to just assume that's what's everyone's talking about.
There are so many of these little tools coming and going these days it's hard to keep track. Some of them might end up mattering, but most of them probably won't.
Mario Zechner wrote Pi, an agent framework, and wrote Pi (yes the names are confusing), a coding harness (like Claude Code) on top of it. OpenClaw uses Pi the framework, so now Mario Zechner is joining Armin Ronacher's company.
Taken verbatim "Maybe you've heard about the little app called OpenClaw. OpenClaw is powered by pi. That made me collateral of Peter's success. Especially after Armin thought it's a good idea to tell the whole world about the relationship between OpenClaw and pi on his blog."
Having followed a bit of their work this makes absolute sense and I'm excited to see what it enables.
For those that don't know Armin, he's the creator of flask among many things and has some cool projects like around like gondolin.
As for pi, you should absolutely try it out if you've used opencode/continue-dev or even if you've used the less open cloud vendor coding harnesses like Claude/Codex.
I do agree that they write in a way that requires context.
Context: Mario Zechner is the creator of the pi coding harness which powers OpenClaw. OpenClaw is made by Peter Steinberger, a friend of Mario Zechner. Armin is another friend who made public that OpenClaw is based on pi.
Pi itself is a minimalist coding harness with a tiny 1500 token system message and only read, edit and bash as tools. I only discovered it a few weeks ago and it is surprisingly powerful with a local Qwen3.5-35B - especially as it allows to keep the context low.
Mario's blog posts are not easily digestible (imho) until you have read a few of them but they have plenty of profound thinking. His blog is for me the first one in years where I have spent an hour to read several posts.
Mario is deeply rooted in the OSS system and basically that is what he is talking about here in this post. That said, I have no idea what earendil is doing, except that it is based on pi.
Edit: My personal take - "I've sold out" is very much Austrian style because actually it is the opposite. To quote one thing from the post:
"Then Miguel and Nat approached us. Long story short: we sold RoboVM to Xamarin. A short while later Xamarin closed-sourced our open-source RoboVM core, quickly followed by Xamarin selling to Microsoft. Then Microsoft shut down RoboVM immediately.
While there was some monetary gain, everything about this fucking sucked."
So Mario did a lot of vetting to hopefully avoid this from happening again.
Understandable, I'd probably do the same in his position. Still sucks, we've seen this pattern a thousands times before and what happens next is pretty obvious.
I was prototyping something with pi under the hood for a personal project, going to switch off it now.
> Lefos uses a credit-based billing system. New accounts receive a limited number of starter credits at no cost. Usage of AI features consumes credits.
> When your credits run out, you can subscribe to a paid plan to receive additional credits each billing cycle. Subscriptions are processed through Polar, our billing provider. You can manage or cancel your subscription at any time from your account settings.
Been following Mario and Armin (much longer), and this is a good move for all parties involved. Would have been bad if Pi went the same direction as RoboVM (mentioned in the post). Earendil, as a company, is not clear for me yet but one of the projects Armin is working on that's part of this is Absurd[0], which is also an interesting project. Absurd, like Pi, is minimal and let's you have full control.
I found out last night via pi.dev. And the new repo of pi didn’t exist yet.
I have been working with pi-mono locally for a few months now. Great code base to study. Much higher quality than CC. (I have posted a gist analysis before.)
Will keep an eye on the work of these talented engineers and entrepreneurs. Good luck guys!
Eventually, everyone has a "price" or a "figure" they are thinking about in their heads. That's fine and I don't think Mario made any promises here about Pi.
However, the worst ones are the ones who preach to others about never selling out whilst telling others that they are there for the long-term publicly, but will privately sell out the minute the offer is greater and exclusive to them.
The point here is not make such promises. People who preach one thing and then are tested to do another are the ones to avoid.
> The one thing that differentiated Armin from other internet trolls was the way he conducted himself in these heated discussions. He was never emotional or aggressive. Our discussions would either end in cordial disagreement, or a newfound common understanding. That's extremely rare on the internet.
Ah haha so armin is also an Internet troll, right? For example if I said, one thing that sets the "Concorde apart from other commercial airliners, ..." I am saying the Concorde is a commercial airliner.
Piloting OSS is all the work of any other business and more. It is a more challenging path and all your decisions are out in the open for scrutiny. He made a decision to put his family first, and I respect that. It seems like there is an alternative to selling out, trusting the project to other people committed to OSS. The beauty of OSS is that this path is still available for people.
Pi is my preferred coding agent and I'm happy it lands in good hands. At this point the only reason to use CC is access to Opus. I think open source will end up winning the coding agents race among developers at least. We just need a 30B size model with Opus like capabilities for coding. Frontier labs will dominate the Desktop / Web.
> In May, the three of us ended up at Peter's flat in Vienna and built our first vibe slopped project together: VibeTunnel.
May be overthinking this but I'm geniunely curious how that was done practically speaking? Standard git branch and merge or everyone sitting around deciding what prompt to write?
Mario having to write this many words to justify this decision alone is a red flag already. The fact I can't understand what Earendil is after reading this many words is an even bigger red flag.
But who am I to judge? If I made a project as popular as pi I'd sell out so fast.
pi is great and made popular some things that are really valuable, that hopefully spread to more projects (arbitrary forking with /tree, system prompt transparency and control). i was hoping to use it on a few projects but needed something to embed, and it didn't quite fit the bill. ended up building https://github.com/zackham/aloop which i am using in coordination with https://stepwise.run/ - reach if you're interested, both under active dev and deployed in systems doing real work.
> I think Armin and I first met 14 years ago, on the r/austria subreddit. We did not align politically on many things, him being a "hyper neoliberal" and me being a "social democrat" (at least according to what I feel was our mutual impression of each other). Any time I saw that @mitsuhiko handle in a thread, I felt the urge to tell someone they are wrong on the internet.
> Over coffee, Armin and I found we had more in common than we thought. Not only politically, but also in the way we think about software, and OSS specifically. In my recollection, we became actual friends that day, even if we didn't meet again for many years in real life.
This is probably the "highest value" part of that whole blog post, as this is something I see so frequently in the real world. People don't give others a chance to just be humans with conflicting views and opinions, and instead try to assign a label to the other part as quickly as possible, then they apply the same "rules of engagement" with that person, as anyone else who deserved to get that label. But once you forgo it, you realize how much you have in common even with your "worst enemies".
It goes both ways too, and the more closed up you are in that regard, others will treat you the same. But you miss out on so many interesting thoughts, ideas and conversations, when you limit yourself to labels and not realizing how diverse and interesting even the most "boring person" could be, given the right questions and the right conversation underlay.
I think it's a bit sad that we often say people "Sold out". Sometimes, I agree, but often, I point out that until the lady at the grocery store stops asking me for money when I walk up to check out, I need to pay my bills to eat.
I contribute to open source projects, but none of them to date could support me buying much more than a beer. If one took off such that I could "live" off it, I would be happy to leave my current job and dive all in. Until then, I just keep plodding along.
This is so disappointing. Finally we had a fantastic, fully OSS, non-profit harness. Very extensible, well-made, minimal, untainted. None of the baggage of OpenCode both in terms of codebase as well as its.. "passionate" leadership, to put it mildly.
> Earendil is a public benefit corporation
Ah, so like OpenAI then.
> But I've also learned what I do not want. I do not want to build my own company around pi. We have a four-year-old kid. I want to watch and help him grow up as best as I can. This is, first and foremost, what I want. Everything else is secondary to that. In the past 2 months, he cried a lot because "daddy isn't here". I never ever want to experience that again.
That's completely fair. And above it, you sketch exactly what you could've done instead to solve this:
> I mostly handed over the reins to a beautiful team of core contributors in 2016, who to this day keep the project well maintained. I never commercialized libGDX, unless you consider it commercialization to build a proprietary piece of software like Spine on top of it.
Sounds like the above worked great, and this would've been the obvious option to do once again.
> part of me wants to take this further. That includes building a team. It also includes commercialization to feed the team, done in a way that doesn't repeat the shit I lived through with RoboVM.
So this is the only part that really answers the "why" - you want to earn a living from working on Pi, and presumably (?) believe you can't achieve that with OSS. I think you're wrong, and belong to the 0.001% of OSS projects that can earn a very nice living from working on Pi without taking this step. I'm not exaggerating, I would fully agree that the number of OSS projects where this is possible is exceedingly small. But this is one of them. If you don't believe that then fair enough, I guess, though I'm curious why you believe that. Because there clearly exist a good number of OSS projects that make their lead developer a very comfortable living. Which condition do those projects satisfy that Pi doesn't?
If that's not it, then the article doesn't really answer the "why" despite lots of text that appears to do so.
You obviously owe me, or anyone really, nothing. So far all you've done is contribute for free. But if you're going to write this kind of article to clearly do a little bit of soul searching, assuaging fears and "make things public" to stop them weighing on your mind, then it looks better to go all the way and state things in plain terms.
Happy for Mario, Pi is the best harness I've ever tried. But overall disappointed by this decision. "This time everything is different" until it's not.
Yet another bait and switch plays out - build clout on the goodwill of open source and execute the plan at the opportune moment.
I may understand the decision but I sure as hell don't respect it - cashing out and prioritizing your family, a very human thing to do, at a glance it almost even seems noble.
187 comments
This was a solid letter to the fans. I get why it’s disappointing to some, but it sounds like it was the right move for them personally. For people who’ve earned that kind of credibility, I say congrats on the move.
I switched a few months ago and have not looked back. Unfortunately Anthropic blocked access from Claude Subscription users today, but that's a different story.
I'm not sure if this library or if the AI tool itself really matter all that much, but a lot of people seem to think that they do, or will anyways, which is probably why this post has no context. Because the author assumes that both the library and the tool are well known, but I think they're only well known by those in the AI world.
You know how it is. You only know what you know, and it's hard to remember what it was like when you didn't know. When you're around people who talk about the same things all the time, it's easy to just assume that's what's everyone's talking about.
There are so many of these little tools coming and going these days it's hard to keep track. Some of them might end up mattering, but most of them probably won't.
For those that don't know Armin, he's the creator of flask among many things and has some cool projects like around like gondolin.
As for pi, you should absolutely try it out if you've used opencode/continue-dev or even if you've used the less open cloud vendor coding harnesses like Claude/Codex.
I do agree that they write in a way that requires context.
Pi itself is a minimalist coding harness with a tiny 1500 token system message and only read, edit and bash as tools. I only discovered it a few weeks ago and it is surprisingly powerful with a local Qwen3.5-35B - especially as it allows to keep the context low.
Mario's blog posts are not easily digestible (imho) until you have read a few of them but they have plenty of profound thinking. His blog is for me the first one in years where I have spent an hour to read several posts.
Mario is deeply rooted in the OSS system and basically that is what he is talking about here in this post. That said, I have no idea what earendil is doing, except that it is based on pi.
Edit: My personal take - "I've sold out" is very much Austrian style because actually it is the opposite. To quote one thing from the post:
"Then Miguel and Nat approached us. Long story short: we sold RoboVM to Xamarin. A short while later Xamarin closed-sourced our open-source RoboVM core, quickly followed by Xamarin selling to Microsoft. Then Microsoft shut down RoboVM immediately.
While there was some monetary gain, everything about this fucking sucked."
So Mario did a lot of vetting to hopefully avoid this from happening again.
I was prototyping something with pi under the hood for a personal project, going to switch off it now.
Shameless plug, yes, but it's free, so I think it's fair :)
And if they mess it up, it’ll be easy enough to fork.
https://lefos.com/about
Apparently it’s possible to give it access to much of your Google account:
https://lefos.com/terms
I didn’t see a pricing page, but there is this:
> Lefos uses a credit-based billing system. New accounts receive a limited number of starter credits at no cost. Usage of AI features consumes credits.
> When your credits run out, you can subscribe to a paid plan to receive additional credits each billing cycle. Subscriptions are processed through Polar, our billing provider. You can manage or cancel your subscription at any time from your account settings.
[0] - https://github.com/earendil-works/absurd
I have been working with pi-mono locally for a few months now. Great code base to study. Much higher quality than CC. (I have posted a gist analysis before.)
Will keep an eye on the work of these talented engineers and entrepreneurs. Good luck guys!
However, the worst ones are the ones who preach to others about never selling out whilst telling others that they are there for the long-term publicly, but will privately sell out the minute the offer is greater and exclusive to them.
The point here is not make such promises. People who preach one thing and then are tested to do another are the ones to avoid.
> The one thing that differentiated Armin from other internet trolls was the way he conducted himself in these heated discussions. He was never emotional or aggressive. Our discussions would either end in cordial disagreement, or a newfound common understanding. That's extremely rare on the internet.
Ah haha so armin is also an Internet troll, right? For example if I said, one thing that sets the "Concorde apart from other commercial airliners, ..." I am saying the Concorde is a commercial airliner.
> Why would you do that?
https://m.youtube.com/watch?v=-0kcet4aPpQ
> In May, the three of us ended up at Peter's flat in Vienna and built our first vibe slopped project together: VibeTunnel.
May be overthinking this but I'm geniunely curious how that was done practically speaking? Standard git branch and merge or everyone sitting around deciding what prompt to write?
But who am I to judge? If I made a project as popular as pi I'd sell out so fast.
Congrats, and I'm rooting for this to work.
> I think Armin and I first met 14 years ago, on the r/austria subreddit. We did not align politically on many things, him being a "hyper neoliberal" and me being a "social democrat" (at least according to what I feel was our mutual impression of each other). Any time I saw that @mitsuhiko handle in a thread, I felt the urge to tell someone they are wrong on the internet.
> Over coffee, Armin and I found we had more in common than we thought. Not only politically, but also in the way we think about software, and OSS specifically. In my recollection, we became actual friends that day, even if we didn't meet again for many years in real life.
This is probably the "highest value" part of that whole blog post, as this is something I see so frequently in the real world. People don't give others a chance to just be humans with conflicting views and opinions, and instead try to assign a label to the other part as quickly as possible, then they apply the same "rules of engagement" with that person, as anyone else who deserved to get that label. But once you forgo it, you realize how much you have in common even with your "worst enemies".
It goes both ways too, and the more closed up you are in that regard, others will treat you the same. But you miss out on so many interesting thoughts, ideas and conversations, when you limit yourself to labels and not realizing how diverse and interesting even the most "boring person" could be, given the right questions and the right conversation underlay.
https://news.ycombinator.com/item?id=46844822
I contribute to open source projects, but none of them to date could support me buying much more than a beer. If one took off such that I could "live" off it, I would be happy to leave my current job and dive all in. Until then, I just keep plodding along.
The Lefos site immediately throws up a sign in page.
The Earendil site just talks about values.
Just take the negative reactions, (if any) as warnings. They have seen it all before like you have:
+ VC funded
+ LoTR name (really?)
+ “We are not evil I promise”
And the biggest red flag:
> None of the early-stage investors are on my naughty list, quite the opposite.
For now.
>And if you ever feel like we've lost the plot, the fork button on GitHub still works. Always will.
Lol, the attitude. 180 degrees from the community that gave him everything he has. Classic.
> Earendil is a public benefit corporation
Ah, so like OpenAI then.
> But I've also learned what I do not want. I do not want to build my own company around pi. We have a four-year-old kid. I want to watch and help him grow up as best as I can. This is, first and foremost, what I want. Everything else is secondary to that. In the past 2 months, he cried a lot because "daddy isn't here". I never ever want to experience that again.
That's completely fair. And above it, you sketch exactly what you could've done instead to solve this:
> I mostly handed over the reins to a beautiful team of core contributors in 2016, who to this day keep the project well maintained. I never commercialized libGDX, unless you consider it commercialization to build a proprietary piece of software like Spine on top of it.
Sounds like the above worked great, and this would've been the obvious option to do once again.
> part of me wants to take this further. That includes building a team. It also includes commercialization to feed the team, done in a way that doesn't repeat the shit I lived through with RoboVM.
So this is the only part that really answers the "why" - you want to earn a living from working on Pi, and presumably (?) believe you can't achieve that with OSS. I think you're wrong, and belong to the 0.001% of OSS projects that can earn a very nice living from working on Pi without taking this step. I'm not exaggerating, I would fully agree that the number of OSS projects where this is possible is exceedingly small. But this is one of them. If you don't believe that then fair enough, I guess, though I'm curious why you believe that. Because there clearly exist a good number of OSS projects that make their lead developer a very comfortable living. Which condition do those projects satisfy that Pi doesn't?
If that's not it, then the article doesn't really answer the "why" despite lots of text that appears to do so.
You obviously owe me, or anyone really, nothing. So far all you've done is contribute for free. But if you're going to write this kind of article to clearly do a little bit of soul searching, assuaging fears and "make things public" to stop them weighing on your mind, then it looks better to go all the way and state things in plain terms.
> Fair Source and Enterprise
Yet another bait and switch plays out - build clout on the goodwill of open source and execute the plan at the opportune moment.
I may understand the decision but I sure as hell don't respect it - cashing out and prioritizing your family, a very human thing to do, at a glance it almost even seems noble.