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Cal.com is going closed source

cal.com

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Re: Cal.com is going closed source

#171

Post by theahura »

DrammBA wrote: post #56
simonw wrote: post #11

Drew Breunig published a very relevant piece yesterday that came to the opposite conclusion: https://www.dbreunig.com/2026/04/14/cybersecurity-is-proof-o... Since security exploits can now be found by spending tokens, open source is MORE valuable because open source libraries can share that auditing budget while closed source software has to find all the exploits themselves in private. > If Mythos continues to find e…

I have a feeling the real reason is them trying to avoid someone using AI to copyright-wash their product, they're just using security as the excuse.

At risk of self promotion, I think more people should adopt something like the Ship of Theseus license (https://github.com/tilework-tech/nori-skillsets/pull/465/cha...). It's not obvious if this will patch the clean room hole in licensing, but I'd rather see it play out in court than assume opensource is just fully dead

Re: Cal.com is going closed source

#172

Post by shimman »

philipov wrote: post #146
notnullorvoid wrote: post #116

Earlier quoted context omitted.

> The moat of Cal.com is not the code, it's the users who don't want to migrate. That's a very weak moat unless you have something else like the friction of network dependence similar to a social network.

Sunk cost is sufficient friction for most people even without network dependence.

For a meeting scheduler site? I feel like you're overestimating the capabilities of something that is akin to college graduate project.

This company does not seem healthy at all:

https://getlatka.com/companies/calcom

I agree with the other poster that mention this is likely a publicity stunt but all it's really showing is that VC is still incredibly stupid with their money. All the more reason to seize it from them then properly fund useful software and not subsidize vanity projects for stanford grads.

Re: Cal.com is going closed source

#173

Post by theahura »

I'm sorta suspicious. I don’t really think this is why they are moving to closed source. It’s true that there is more security risk, but that actually justifies being open source, because open source tooling can spend more tokens hardening itself against security vulns than closed source tooling (at least, that’s the theory). My strong hunch is they are moving to closed source because it is now trivial to copy a product with AI clean rooms. Which, tbf, is a totally valid reason to move closed source. But I'd want to see more adoption of something like the Ship of Theseus license (https://github.com/tilework-tech/nori-skillsets/pull/465/cha...) before giving up on open source entirely

Re: Cal.com is going closed source

#174

Post by sashimimono »

ryanleesipes wrote: post #143

Head of Thunderbird project here. Our scheduling tool, Thunderbird Appointment, will always be open source. Repo here: https:// github.com/thunderbird/appointment Come talk to us and build with us. We'll help you replace Cal.com

I would like to, but... have you tried to use thunderbird on an "older" linux laptop nowadays? Even with 8 gigs of ram, and a non-fancy memory-saving windowmanager, thunderbird is almost unusable now (large imap mbox), firefox even worse. I don't see why all that additional bloat is needed, or wanted. Please keep in mind, that a lot(!) of people are not able to afford buying new hardware every now and then anymore. And this is getting worse. First the pandemic, then the war in Ukraine, now the war in Middle-East. Shortage of ram/storage/everything (thanks ai) and massivly increased costs of energy, housing, food, insurance, everything. And in the years to come, I am afraid, that will be getting worse. Please think about it, when adding the "next cool feature", 'Keep the internet affordable'. --thunderbird user since 1.0

Re: Cal.com is going closed source

#175

Post by devmor »

theahura wrote: post #171
DrammBA wrote: post #56

Earlier quoted context omitted.

I have a feeling the real reason is them trying to avoid someone using AI to copyright-wash their product, they're just using security as the excuse.

At risk of self promotion, I think more people should adopt something like the Ship of Theseus license ( https://github.com/tilework-tech/nori-skillsets/pull/465/cha... ). It's not obvious if this will patch the clean room hole in licensing, but I'd rather see it play out in court than assume opensource is just fully dead

I cannot imagine that license addendum is legally enforceable (let alone provable) in most jurisdictions on earth but it is interesting.

Re: Cal.com is going closed source

#176

Post by hedora »

sashimimono wrote: post #174
ryanleesipes wrote: post #143

Head of Thunderbird project here. Our scheduling tool, Thunderbird Appointment, will always be open source. Repo here: https:// github.com/thunderbird/appointment Come talk to us and build with us. We'll help you replace Cal.com

I would like to, but... have you tried to use thunderbird on an "older" linux laptop nowadays? Even with 8 gigs of ram, and a non-fancy memory-saving windowmanager, thunderbird is almost unusable now (large imap mbox), firefox even worse. I don't see why all that additional bloat is needed, or wanted. Please keep in mind, that a lot(!) of people are not able to afford buying new hardware every now and then anymore. A…

Regarding FF: Something is probably wrong with your install, or the websites you have open.

As a datapoint: FF + Chrome with lots of stuff open uses 2.6GB on my machine. With XFCE and a GB of other apps, it’s using about 4GB. 15 year old machine. Perf is fine.

Re: Cal.com is going closed source

#177

Post by usernametaken29 »

Just a random thought. Up until yesterday this project was open source. The code base won’t be rewritten tomorrow. More likely is that conserved parts of the source code, something like 90% will just remain the same. Particularly the core database schema around users and security are likely to stay the same. Since the old code is already out there what’s stopping me from exploiting the software as it was? This looks an awful lot like marketing to me, and not like real security concerns.

Re: Cal.com is going closed source

#179

Post by ezekg »

liamgm wrote: post #119
ezekg wrote: post #81

Earlier quoted context omitted.

I mean, they were a COSS startup using the AGPLv3, so checks out. :)

Changed the license of the foss version cal.diy to MIT . Grace in disguise , now enterprise user can host cal.diy without worries of viral licensing .

That was my point. Only reason they were using the AGPLv3 in the first place was as a hush hush non-compete, and now that that doesn't matter...
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