Great work, I am strongly in favor of using vim.pack

Startup Time Diff
This will differ based on hardware, but I was getting 65-75ms with this branch and 42-47ms with the master branch.
I measured using nvim --startuptime startup.log and looking at the bottom of the log file.

Lazy Loading
I don't think it's necessary, but maybe add a note saying to look into autocommands, MiniMisc, lazy.nvim, etc. if concerned.

I also did some testing of my own and the results are promising :)

It seems that after adding vim.loader.enable the vim.pack is only 3-4 ms slower than lazy (both of them were measured after a couple of restarts to allow them to compile the bytecode).

Relevant system info:

orip@Ori-pc ~/.c/upstream-kickstart (refactor/vim.pack)> inxi
CPU: 8-core AMD Ryzen 7 5800X (-MT MCP-) speed/min/max: 4195/614/5363 MHz
Kernel: 7.0.0-200.nobara.fc43.x86_64 x86_64 Up: 2d 13h 8m
Mem: 9.5/31.25 GiB (30.4%) Storage: 5.48 TiB (12.0% used) Procs: 511
Shell: fish inxi: 3.3.40

orip@Ori-pc ~/.c/upstream-kickstart (refactor/vim.pack)> nvim --version
NVIM v0.12.1
Build type: Release
LuaJIT 2.1.1774638290

orip@Ori-pc ~/.c/upstream-kickstart (refactor/vim.pack)> ghostty --version
Ghostty 1.3.1

Version
  - version: 1.3.1
  - channel: stable
Build Config
  - Zig version   : 0.15.2
  - build mode    : .ReleaseFast
  - app runtime   : .gtk
  - font engine   : .fontconfig_freetype
  - renderer      : renderer.generic.Renderer(renderer.OpenGL)
  - libxev        : io_uring
  - kernel version: 7.0.0-200.nobara.fc43.x86_64
  - desktop env   : other
  - GTK version   :
    build         : 4.20.3
    runtime       : 4.20.4
  - libadwaita    : enabled
    build         : 1.8.4
    runtime       : 1.8.5
  - libX11        : enabled
  - libwayland    : enabled

I just converted my own configs to use vim.pack exclusively without any issues; and the startup time is not noticeable at all between vim.pack and lazy.nvim.

Given that the current config uses lazy require at each relevant point in the file, I would favor replicating that with vim.pack. I think it would be clearer for users that all related code are grouped together.

I reordered the sections a bit, and surrounded each of them do ... end so it would be easier to know where they start/end.
This also makes them foldable if it is enabled (maybe we should explain that and enable it by default?).

I think this is pretty much ready, so I would love to hear some feedback before merging - especially about the comments, explanations, and overall structure :)

I don't have any opinion on lazy/pack.

Just the request, if kickstart switches to vim.pack, please add a doc for how to migrate lazy based config for the newbs.

And maybe add a min Version check for vim 0.12 somewhere.

@Christoph-Raab In case you are looking for some resources to get started with right now, I would recommend reading this blog from the creator of vim.pack. It's got plenty of resources and a linked youtube video as well. The relevant section where migration from lazy.nvim is discussed is here but I would suggest reading the entire thing start to finish.

I think vim.pack.add near each relevant require is better option than one big vim.pack.add in the beginning.

I think vim.pack.add near each relevant require is better option than one big vim.pack.add in the beginning.

I have added this in the latest commit. WDYT?

It looks so much better now, it's much clearer and easier for beginners to see what came from where and what activated it. As someone who uses the vanilla version of kickstart.nvim, I really like it.

I must admit that if there are any differences in file opening speed or performance, I don't see them between lazy.nvim (master) and vim.pack + vim.loader (f9b6223) - or maybe my eyes are that bad.