GravityKit
GravityKit folds every GravityView extension into one Pro plugin.
A side-by-side editorial comparison of Firecracker and Ably — release velocity, themes, recent moves, and the top alternatives to consider.
| Feature | Firecracker | Ably |
|---|---|---|
| Sector | Infra & APIs | Infra & APIs |
| Velocity score | 3.8 | 7.5 |
| Sparks · 30d | 1 | 2 |
| Top themes | microvm, virtualization, confidential computing, aws nitro | ai transport, realtime messaging, agents, mau-billing |
| Last editorial update | 4d ago | 21h ago |
| Website | Visit → | — |
Firecracker can now run microVMs on Nitro instead of KVM, with the same API.
Firecracker is the open-source microVM monitor behind AWS Lambda and Fargate. 2026 brought PCI virtio hotplug in developer preview (1.16), virtio device reset and richer metrics (1.17), and now 1.18.0 adds Nitro Sandboxes: Firecracker can drive the Nitro Enclaves driver instead of /dev/kvm to launch VMs the Nitro Hypervisor carves out of the parent EC2 instance. The existing API, jailer and virtio device model stay the same, and a new PUT /enclave endpoint selects confidential or direct mode.
Ably's AI Transport hits 1.0 and plugs straight into Vercel's useChat with resumable streams.
Ably is repositioning its realtime pub/sub network as the transport layer for AI agent output. AI Transport JS 1.0 runs on ordinary Pub/Sub channels and ships adaptors for the Vercel AI SDK, OpenAI Responses API and AG-UI, plus a useChat transport that resumes a stream after a reload. It lands a week after the switch to monthly-active-user pricing and breaking SDK majors that split every client into device and server packages.
Firecracker is the open-source microVM monitor behind AWS Lambda and Fargate. 2026 brought PCI virtio hotplug in developer preview (1.16), virtio device reset and richer metrics (1.17), and now 1.18.0 adds Nitro Sandboxes: Firecracker can drive the Nitro Enclaves driver instead of /dev/kvm to launch VMs the Nitro Hypervisor carves out of the parent EC2 instance. The existing API, jailer and virtio device model stay the same, and a new PUT /enclave endpoint selects confidential or direct mode.
The project is widening what a Firecracker microVM can be without changing how operators drive it: hotplug and reset made the VM lifecycle more flexible, and Nitro support makes the hypervisor backend swappable. Patch releases keep landing on several stable lines at once, so the maintainers are supporting older minors while the feature surface grows.
Expect 1.18.x patches that fix Nitro Sandbox edge cases and documentation on which devices and snapshot features work in confidential mode; the release does not say whether Nitro support will leave preview or reach feature parity with KVM.
Ably is repositioning its realtime pub/sub network as the transport layer for AI agent output. AI Transport JS 1.0 runs on ordinary Pub/Sub channels and ships adaptors for the Vercel AI SDK, OpenAI Responses API and AG-UI, plus a useChat transport that resumes a stream after a reload. It lands a week after the switch to monthly-active-user pricing and breaking SDK majors that split every client into device and server packages.
The November releases fit one plan: split clients so MAU billing can count end users, then make the AI layer a thin adaptor on top of the same channels used for chat, presence and LiveObjects. Server-side additions in Java and JS (HTTP LiveObjects, channel pools, a Temporal plugin) point at agent backends as the intended publisher.
Expect more agent framework adaptors and server SDKs reaching AI Transport parity, with Chat and LiveObjects examples built around agents joining human conversations.
Other Infra & APIs products tracked by Sparkpulse, ranked by recent ship velocity. Each card links to a full editorial trajectory and lets you pivot into a head-to-head comparison with either Firecracker or Ably.
GravityKit folds every GravityView extension into one Pro plugin.
Payload's v4 beta.9 keeps every past image crop and raises the Node floor again.
Nautobot 3.3 alpha 2 adds test helpers and a cable location filter after 3.2.9's token-leak fix.
Clair 4.10 RC can read SBOMs to match Java vulnerabilities.
Shuffle tags builds almost daily, but the notes are empty.
KrakenD's community edition is shipping only dependency bumps.
See all Firecracker alternatives → · See all Ably alternatives →
Latest ship moves from both products, interleaved chronologically. ⚡ = editorial spark.
They serve adjacent needs but don't currently overlap on shipped themes. Ably is currently shipping more aggressively (velocity 7.5 vs 3.8), with 2 editorial sparks in the last 30 days against 1. See the at-a-glance table above for a side-by-side breakdown of velocity, recent sparks, and editorial themes.
Sparkpulse doesn't pick a winner — we score release velocity, not feature parity. Ably is currently shipping more aggressively (velocity 7.5 vs 3.8), with 2 editorial sparks in the last 30 days against 1. For your specific use case, the alternatives sections above list other Infra & APIs products to evaluate alongside.
Top Firecracker alternatives in Infra & APIs are ranked by recent ship velocity. Browse the "Firecracker alternatives" section above for the current picks, or visit /alternatives/firecracker for the full list with editorial commentary on each.
Top Ably alternatives in Infra & APIs are ranked by recent ship velocity. Browse the "Ably alternatives" section above for the current picks, or visit /alternatives/ably for the full list with editorial commentary on each.