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MPW and the development starter pack

MPW is an optional onboarding dependency, handled exactly the way CarbonLib is: the host fetches one checksum-pinned artifact on request, saves it in the operator's Application Support drop, and builds it into the personalized setup image. No MPW bytes live in this repository and no release output carries them.
Catalog id mpw-gm
Download https://old.mac.gdn/apps/mpw-gm.img__0.bin
Source page Macintosh Garden
SHA-1 2a57aa9364a165ea0ddfa0611003ee1f13984715
Saved as Dependencies/mpw-gm.img.bin
Delivery unchanged — the download is already a MacBinary NDIF image
On the setup image Dependencies/MPW-GM.img, forks and rohd/ddsk intact

Press Get beside MPW in the Onboarding window, or drop an equivalent file into ~/Library/Application Support/New Old World/Onboarding/ Dependencies/ yourself. The checksum is verified before the file is written; a mismatch refuses with both digests named. The classic download page offers the same artifact, and lists the source page when the host does not have it yet.

Nothing pre-registers a toolchain. On the classic Mac a person opens the image, copies the MPW folder to the hard disk, and selects that folder in NOW's Projects page; the guest qualifies it there and mints a fresh opaque toolchain identity.

A generic operator-supplied pack

now.development-starter-pack/1 remains for a payload that is not the pinned MPW image — a curated pack an operator assembles themselves. It is a manifest plus a digest-pinned artifact in the same Dependencies/ folder, and the setup-image build refuses a missing artifact, a second manifest, a byte-count or SHA-256 mismatch, or a qualification claim the product does not implement. The checked-in template lives at packaging/development-starter-pack/Development Starter Pack.manifest.json and its zero artifact measurements are deliberately unshippable.

Delivery to the guest

The setup image is the NDIF/PPC lane: MPW rides the image's Dependencies folder under its classic name, and the Read Me gains registration instructions whenever the image carries it. A starter-pack manifest is host validation metadata and never crosses to the guest. The image is bounded at 128 MB; the MPW GM image is roughly 25 MB, so it fits beside the application, Extension, and CarbonLib installer. MPW does not fit the floppy-sized media a 68K bootstrap uses, so there is no 68K lane.

For an already-connected guest, the guest-files upload lane (now_guest_files_upload_begin / append / commit) can carry the same MacBinary image directly instead of rebuilding setup media.

Copy the whole MPW-GM folder — MPW and Interfaces&Libraries together — to a writable disk, then register the MPW folder inside the copy. Two measured failure shapes hide here. Mounting the image is not enough: a ToolServer launched from the read-only volume cannot run its own tools, and the build fails on its first action with status −1 and an empty transcript (measured four ways on one emulator guest, 2026-08-19 — the matrix is in open issues). And a copy of the MPW folder ALONE is not enough either: MPW's Startup resolves Interfaces&Libraries as the registered folder's sibling ({MPW}::), so the lone copy qualifies — the structural-1 probe checks ToolServer and MrC, never headers — and then fails every compile with "unable to open input file 'MacTypes.h'" (measured 2026-08-19, same rig). The setup image's Read Me carries both instructions whenever it carries MPW.

Qualification is the guest's, and the manifest may not overclaim

The manifest's qualification.probe must name a probe the product implements, and requiredItems must be exactly the items that probe measures. Today that set is one entry:

Probe Measured items Where
structural-1 ToolServer (file) and Tools:MrC (file inside the Tools folder), immediate children of the registered folder now-guest-ppc/src/development/development_toolchain_mac.c

A manifest naming any other probe, or claiming items structural-1 never checks, is refused. This keeps now_development_environment honest: the rows it relays — toolchain identity, qualification verdict, ToolServer and MrC presence — are the same measurements the manifest promised, performed by the guest on the human-registered folder. not found there means "not measured in the registered folder"; the guest never scans volumes for MPW and delivery of a pack does not register anything by itself.

Initial platform matrix

Guest Useful initial toolchain What the pack may ship
System 7.1–7.6, 68K MPW with 68K C/Rez/linker and matching Universal Interfaces Not a lane yet: MPW does not fit 68K bootstrap media. Qualify on a 68K guest before claiming it; a PPC qualification is not evidence.
System 7.1.2–8.6, PowerPC MPW with PPC C/Rez/PPCLink and matching interfaces/libraries The pinned mpw-gm download covers this, and it is the current NOW guest-native backend.
Mac OS 8.6–9.2.2, PowerPC/CarbonLib MPW plus Universal Interfaces containing the intended CarbonLib surface Same download; qualify compiler, linker, ToolServer and target interfaces together.
Mac OS 8.1–9.2.2, PowerPC CodeWarrior 6/7 can target classic and Carbon applications Do not redistribute: contemporary releases were commercial per-seat products. CodeKitten may eventually drive a human-installed copy through a separate backend.

Apple later made MPW available without purchase, which is why it can be fetched the way CarbonLib is. That is not the same as a right to redistribute it: nothing here is committed to Git or placed in a release output, and a generic pack's manifest keeps redistribution as unknown until the exact archived license for its exact payload is recorded. CodeWarrior remains proprietary and is not a payload at all.

The matrix is intentionally about a useful baseline, not universal coverage. One PPC MPW qualification does not establish that its tools target every 68K system, and a System 7 build does not imply CarbonLib compatibility.

Fixture provenance

Every VM or metal receipt using the pack records:

  • base-image SHA-256;
  • the artifact SHA-1 the catalog pins, or a pack manifest's SHA-256;
  • anchor-policy digest;
  • guest build and resident fingerprint;
  • independently qualified worker and toolchain identities.

No absolute host path, HFS directory ID, or registration from another machine belongs in the manifest or receipt.

Research sources