You’re touching on a few different points so I’ll try to cover everything.
- We do build on top OSS (just not those programs you listed - see https://pspdfkit.com/legal/acknowledgements/processor-acknow... for a complete list). The layer we build is quite large though, and it would take many person-years to replicate in its entirety. It’s possible though that you don’t need that at all and a focused program that wraps other ones might do the trick for your use case.
- If you build a product based on our tech, you’re taking a conscious decision about risk: while I do think we’re gonna be in business in 10 years (we have solid revenue and last year we got backed by a large investor, Insight), that we would version APIs and support you (not just during upgrades), the reality is that it is indeed possible that we’re not gonna be around anymore, like every other company on the planet. As a consumer, this is the reality for most of the things we buy nowadays. We do take deprecation seriously, as sell SDKs, and I’m sure in case of the company shutting down you would have enough time to migrate.
- Depending on what you need to build, using our product may shortcut your development time by a large factor. It may not, if you just need to rotate pages of a PDF document and there’s a reliable OSS package that does that in your language of choice. It really depends on what you need to do.
- Even if you package everything with OSS, waiting 10 years is a sufficiently large amount of time that it may not work and you have to fork and rebuild yourself. It’s a different type of risk, but still a risk. 10 years ago Docker had just been launched. Whether you build something on OSS or commercial, you would wanna test things once a year to see if they still work or keep up with security and bug fixes.
Ultimately, there are situations where the approach you described is sound: for example, I do my taxes in plain text accounting, using ledger and emacs. I generate the reporting via a couple of Ruby scripts. I do that exactly because I care about longevity: I do my taxes once a year, I don’t wanna spend time fixing the toolchain every time I have to do them. Yet every year I hit a couple of snags I have to fix, but I consider that acceptable.