I realize this isn't a fresh thread, but I'm just seeing it now, and thought I might be able to add some thoughts you peeps may not have considered. (In this way it's an "update"—optional, of course.
) If there's a newer thread on this topic, feel free to move this to it.
First, are you sure Calibre doesn't already have an updater? In Preferences > Behavior, the very first item is "Notify when a new version is available", and it's selected by default... What's up with that? Did some updater-favouring developer sneak it in to be cheeky?
For what it's worth, bundled update-checkers are a common, nearly expected feature these days. And I agree that, no matter what, update-checking should be optional, NOT activated by default.
Some of you here are worried that people with Compulsive Update Disorder (CUD—that's gotta be a thing, doesn't it, for the acronym alone?) will jam Calibre's servers. To limit gratuitous downloads, the updater, on finding a new version, should show a "What's new" window. I've worked with many obsessive IT peeps (and at least two who weren't), and in most cases, detail and reliability trump blind installing. Because so much can go wrong with software, many users would decline updating if there weren't solid reasons to do so, when everything already works.
If obsessive updaters were prominently shown exactly what had changed, I think it's most likely they'd (obsessively, LOL) read the details; determine if any of the changes would benefit them; then update only if that were true; and that otherwise they'd click Cancel. (That's my own behaviour—and I'm usually happy to install software for trivial reasons.)
With the current system of having to manually check for updates, I have no idea how easily these details are seen; I suppose it depends on which of the many Calibre sources one uses. (It may also be influenced by how many reasons one has to create lists with semicolons. Punctuation is a powerful thing for those still versed in that arcane art.)
Also, I realize that in Calibre's case, this may be unlikely—but another legitimate reason for auto-checking for new versions is that they can fix serious problems. Coders do the best they can, but no one can anticipate
all possible combinations of user circumstances. If a version of something has a security vulnerability, may unintentionally change or delete user content, or has other pressing issues, it doesn't announce this itself unless it's equipped to go online; then it can make it clear to the user how important it is to update.
Finally, if the decision is made to give Calibre one of these dandy 21st-century-style updaters (and by cracky, you can reckon what a hubbub that'd raise with the folks round the pickle barrel over to the general store!), it shouldn't be necessary to "reinvent the wheel" by writing one. In-app updating (or simply new-version checking) is so
de rigueur now, there must be at least several OS plug-'n'-play projects addressing it. Cheers!