Xorgproto Debuts, Reflecting X.Org Server Development Slowing Down
Red Hat's Adam Jackson wrote in announcing xorgproto 2018.1, "This package combines the protocol headers, which were formerly scattered in individual packages. At this point none of them are changing rapidly enough to justify such fine granularity, particularly when what changes do occur tend to affect multiple extensions at once (Present and DRI3 for example)."
Basically with the low churn of the protocol headers the past few years, they are now being gathered all in one repository and tagged as one release rather than separate releases for each of the different protocols. Xorgproto though maintains separate pkg-config modules as to not confuse existing build systems, etc.
Xorgproto supports both Autotools and Meson based installation. Moving forward they are likely to default to the Meson-based build system due to its speed and convenience.
Among the protocol headers making up xorgproto are for Composite, Damage, DMX, DRI2, DRI3, Fonts, GL, Panoramix, Present, RandR, Xext, xf86dri, Xinerama, and many other extensions. Besides the 2018.1 release packages, these protocol headers are now housed in this Git repository.