Downloads / Engineering preview / September 19, 2026
Choose the right artifact.¶
Current Status: Non-installing engineering preview; the Installation Utility is not fully working. macOS boot, physical desktop, Metal, installation, Recovery, DFU and real-hardware qualification remain unverified.
Target State: Verified, reproducible release artifacts with clear provenance and a complete Installation Utility qualified on real Intel Macs.
There is no supported installation release yet. The preview contains no macOS payload. An ISO or EFI file does not establish macOS bootability, a working Metal driver or a completed installation. No real Intel Mac is currently qualified.
Installation Utility engineering preview¶
Release target: engineering-preview-20260919 in 26x86/NextCore. Channel: preview. The ISO and EFI both use the default release-policy build. This profile refuses unsupported or unqualified platforms; it is distinct from the internal research profile used for OVMF planning and read-only GPT tests.
Open the preview release and published assets
Use the release asset list to confirm publication and file availability. The website's link is not a completed download or validation receipt.
The exact 17,641,472-byte ISO was executed under QEMU/OVMF: the utility started and refused the unsupported virtual machine. Its SHA-256 is cd79ef7bfbc8fc3273064662472a37073b0dfa47ace119527b27e08413a4c62f. This bounded refusal check does not qualify any physical Mac or demonstrate installation. The download catalog records final sizes and hashes for each published asset.
Non-installing ISO
nextcore-installation-preview.iso¶
Utility preview image with an EFI entry point. It does not install macOS or bundle its payload, and it does not establish bootability on real hardware. Platform refusal can be the expected result.
Default release policy
EFI binary package¶
Standalone Installation Utility preview entry. It is not the normal macOS loader or a Metal driver. The same unsupported/unqualified-platform policy applies.
Integrity
MANIFEST.sha256¶
Per-file SHA-256 values for the published assets. Match the exact filename and hash before relying on a downloaded file. Hash agreement establishes byte identity, not functional acceptance.
Provenance
release.json¶
Published artifact identity, build profile and validation limits. Keep it with the manifest and downloaded files. Consult the actual release metadata for hashes and sizes; this page does not invent them.
Project license
LICENSES.txt¶
Project and included software license terms and acknowledgments supplied with the preview. Keep this file with the downloaded artifacts and consult it before redistribution.
Check a download¶
- Confirm the repository and exact release tag above.
- Download the selected asset,
MANIFEST.sha256,release.jsonandLICENSES.txtfrom that same release. - Compute the asset's SHA-256 and compare it with the matching filename in the manifest.
- Read the metadata and current acceptance limits. A matching checksum does not qualify a machine or authorize installation.
For example, use Get-FileHash -Algorithm SHA256 .\nextcore-installation-preview.iso in PowerShell, or shasum -a 256 nextcore-installation-preview.iso on macOS. Compare the full value, ignoring letter case only.
Archived engineering firmware¶
prebuiltefi.zip is a separate legacy artifact, not the current supported release. Its primary public EFI source revision is df2c15b8. The manifest pins all seven public module sources and separately identifies private assembly revision 3d3a434dfc9f84dcc1c34a2257f8cf7ceaafd99c; the complete assembly is not publicly downloadable. It predates the current real-Mac admission policy; do not assume it enforces the preview's hardware restrictions. It is not an installation recommendation or a compatibility approval.
Legacy prebuiltefi.zip Legacy archive hash and provenance
The archive contains a baseline EFI/BOOT/BOOTX64.EFI, an empty EFI/OC/config.plist, a separate diagnostics/NXARMJIT.efi, manifest.json, README.txt and embedded LICENSES.txt. Baseline firmware and the diagnostic are different artifacts; the diagnostic must not be relabeled as the normal boot entry. Neither establishes a working macOS installation.
The deployment builds and verifies this legacy archive from its pinned source selection. Its sidecar describes the actual deployed ZIP. Updating the portal or publishing the new utility preview does not update this pin or add the newer hardware policy to the old binaries.
What comes next¶
Physical installation, usable macOS 27, working Metal graphics and hardware-specific Recovery/DFU qualification remain outstanding. Read the six development milestones and hardware qualification requirements before interpreting any preview result.