I don’t think there is anything stopping anyone from building a competing extension pack which is 100% open source, and includes whatever useful features Oracle’s has (RDP is the most obviously useful; some people would benefit from the PXE support). One could potentially reuse code from other (GPL-compatible) open source projects in doing so.
Also, one could make a fork which just rebrands it and removes all references to non-open source components - a bit like what Oracle themselves do to RHEL.
While I agree with this in principal, I'd guess the folks who have the low-level programming chops to execute such a thing are probably a very small list, and of those finding ones which want to spend their weekends(?) trying to keep up with VirtualBox releases (in Subversion of all things!) would be an even smaller list
I think a “just rebrand it and remove all mention of Oracle’s proprietary extension pack” fork wouldn’t require much “low level programming chops” at all. You could probably even automate a lot of it, with manual intervention only required for branding-related changes (which I assume would be rare). My biggest concern about doing it would be the macOS kexts - will Oracle’s trademark policy allow you to redistribute their kext binaries along with a fork, or force you to rebuild them under a new ID? If the later, will Apple approve it (for any special entitlements it might use)? Not an issue for Linux and Windows builds anyway.
Even stuff like RDP, I haven’t looked at the VirtualBox code in detail, but I assume there would be some interfaces to isolate display clients from the low-level technical details of the graphics card emulation-so it might not actually require as much “low-level chops” as you might think.
But your last point about not many people want to spend their weekends on it is spot-on: I myself am not volunteering to do any of this. Between my day job and a young family, don’t have as much time for personal projects as I used to, and what time I do have I’d rather expend towards other goals.
They can't? You mean Oracle can send you an invoice for using the VirtualBox GPL version your Linux distro provides for free? Never heard of that before, could you please share more details?
ORACLE is just releasing this to dupe people into thinking they can use this for free (they can’t).