Dev tools · alternatives · 2026
24 alternatives to Blockdiff – How we built our own file format for VM disk snapshots
Usually, I’m a researcher working on areas like RL for coding agents – but one day I became annoyed by our slow VM startup times. So I took the plunge into systems engineering and built the first version of our VM hypervisor called otterlink. It now powers both our research & all of Devin production workloads. Compared to EC2, otterlink was able to bring down VM startup times by about 10x. The real pain point, however, were EC2’s long snapshot times. We want a lot of flexibility (e.g. forking, rollback and suspending VMs) that all require taking disk snapshots. On EC2 taking disk snapshots…
Blockdiff is a custom file format built for the otterlink VM hypervisor that enables fast disk snapshots for virtual machines. It performs block-level differential snapshots, reducing snapshot times from over 30… Below are 24 products that do a similar job, ranked by how close each is in meaning and then by launch-day votes.
- 1
I wanted to see how fast an isolated code sandbox could start if I never had to boot a fresh VM. So instead of launching a new microVM per execution, I boot Firecracker once with Python and numpy already loaded, then snapshot the full VM state. Every execution after that creates a new KVM VM backed by a `MAP_PRIVATE` mapping of the snapshot memory, so Linux gives me copy-on-write pages automatically. That means each sandbox starts from an already-running Python process inside a real VM, runs the code, and exits. These are real KVM VMs, not containers: separate guest kernel, separate guest…
Mar 2026 · github.com · its alternatives →
- 2
Build and run tiny vms from Dockerfiles. Small and sleek. - ottomatica/slim
2019 · github.com · its alternatives →
- 3
Build and run tiny vms from Dockerfiles. Small and sleek. - GitHub - ottomatica/slim at 2.x
2022 · github.com · its alternatives →
- 4
Convert your product to multiplayer in minutes
2022 · liveblocks.io · its alternatives →
- 5
Hello everyone! I'm currently in a journey to learn and improve my Elixir and Go skills (my daily job uses C++) and looking through my backlog for projects to take on I decided Elixir is the perfect language to write a highly-parallel BitTorrent tracker. So I have spent my free time these last 3 months writing one! Now I think it has enough features to present it to the world (and a docker image to give it a quick try). I know some people see trackers as relics of the past now that DHT and PEX are common but I think they still serve a purpose in today's Internet (purely talking about public…
2025 · github.com · its alternatives →
- 6
Build web applications, with your data, without code
2015 · its alternatives →
- 7
- 8
Distributed Application Starter: Vue front-end, Ethereum / IPFS Backend - redacademy/vue-ethereum-ipfs
2018 · github.com · its alternatives →
- 9
I've invented a new alternative to forking / vendoring / monkey-patching packages in Python. It's a bit like OverlayFS for Python modules - it allows you write modifications for a target module (lower) in a new module (upper), and have these combined in a new virtual module (mount). It works by rewriting imports using AST transformations, then running both the lower and upper module's code in the new Python module. This prevents polluting the global namespace when monkey-patching, and means if you want to make changes to a third-party package, you don't have to take on the…
2025 · github.com · its alternatives →
- 10
- 11
A totally proof-of-concept FoundationDB based network block device backend - dividuum/fdb-nbd
2018 · github.com · its alternatives →
- 12
[I'm the author] Spall is a web-accessible profiler that I made to help my web-dev friends load gigabyte+ JSON traces without lunch-break-long load times. Recently, Spall got experimental support for auto-tracing with binary traces (along with an in-progress native-port, to give it more memory headroom), which was used to help track down and fix some hard-to-spot lock contention issues in the Odin-language compiler. I demoed it at the Handmade Seattle conference in October, https://guide.handmade-seattle.com/c/2022/spall/, with a head-to-head against Perfetto,…
2023 · gravitymoth.com · its alternatives →
- 13
Hey folks! I've been working on something on & (mostly) off for a little over a year, and picked it back up recently because of yet another related frustration at work. I've spent a lot of time ripping out git submodules from repos my teams use, but I've spent an equally large amount of time wondering why there doesn't seem to be a better option for managing arbitrary dependencies across repos in the Year of Our Lord 2024. So, I put together a really early version of such an arbitrary-dependency manager. It's called vdm, and you can find it in the linked URL above & below. I'm sharing mostly…
2024 · github.com · its alternatives →
- 14
I've long wanted to harness QEMU/KVM for my desktop virtual machines, but I'm befuddled by virt-manager's lack of support for working NVIDIA 3D acceleration, dogmatic embrace of ugly XML, and the puzzling UI decision of having to click what seems like 15 buttons to attach an ISO to a VM image. When I further learned that NVIDIA's broken 3D acceleration is the fault of libvirt as opposed to QEMU's virtio driver, I had an idea... Behold, vm-curator! A fast and friendly VM management TUI written in Rust. You can create, configure, organize, and manage VMs directly with QEMU. No libvert. No…
Jan 2026 · github.com · its alternatives →
- 15
Versiobit▲83Archives your files, versioned and audit-proof by Blockchain
2023 · versiobit.com · its alternatives →
- 16
IPFS▲84Peer-to-peer hypermedia protocol for Blockchain powered web
2015 · about.ipfs.io · its alternatives →
- 17
I've built this to make it easy to host your own infra for lightweight VMs at large scale. Intended for exec of AI-generated code, for CICD runners, or for off-chain AI DApps. Mainly to avoid Docker-in-Docker dangers and mess. Super easy to use with CLI / Python SDK, friendly to AI engs who usually don't like to mess with VM orchestration and networking too much. Defense-in-depth philosophy. Would love to get feedback (and contributors: clear & exciting roadmap!), thx
2025 · github.com · its alternatives →
- 18
I kept seeing every npm/pnpm/yarn/bun/uv supply chain post end with the same advice (set a minimum release age, turn off install scripts), and while I know cooldowns are "controversial", they do work. But even if you convince people that they should set cooldowns, it seems many don't end up following through, not sure why, maybe because it means hand-editing five config files in five formats with five different time units, or perhaps the "it won't happen to me" syndrome (or "I'll do it later, it seems complicated" where it's actually very simple). So I created a tool that…
Jun 2026 · github.com · its alternatives →
- 19
Host private Python, Docker, NPM, Debian, and Conda packages. Private package registry with 4.5x faster installs, CVE scanning, and SSO. Up to 80% cheaper than Cloudsmith. Free tier available.
2019 · packagr.app · its alternatives →
- 20AC
I think that asdf (https://asdf-vm.com) was a great idea for a project. It helps consolidate installing and running different programming languages into a similar UX. It also is built with a plugin interface that makes it easy to build support for new languages. However it is so slow. I was just testing `node -v` and it was taking ~900ms. That kind of overhead is completely unusable. My shell prompt uses runtimes inside of it for various things so this effectively makes every command take multiple seconds to complete. So I rebuilt it in Rust but using the same plugin ecosystem so…
2023 · its alternatives →
- 21BI
Self-hosted virtual machines for background coding agents.
Jun 2026 · bastion.computer · its alternatives →
- 22
This project addresses the inefficiencies of traditional Dockerfile-based container builds where each customization layer creates storage bloat through duplicate dependencies from repeated apt-get install commands, network inefficiency from redundant package downloads across different images, and slow iteration cycles requiring full rebuilds of all previous steps. Our solution enables building minimal base images from scratch using debootstrap that precisely include only required components in the initial build, while allowing creation of specialized variants (Java, Kafka, etc.) from these…
2025 · github.com · its alternatives →
- 23
Build and run tiny vms from Dockerfiles. Small and sleek. - ottomatica/slim
2019 · github.com · its alternatives →
- 24
Binary delta encoding tools. Contribute to eerimoq/detools development by creating an account on GitHub.
2020 · github.com · its alternatives →
Also compare
- Sub-millisecond VM sandboxes using CoW memory forking alternatives
- Slim – Build and run tiny VMs from Dockerfiles alternatives
- Slim 2: Create VM from Dockerfile, boots in seconds (+macOS M1/Hyper-V) alternatives
- Storage Block by Liveblocks alternatives
- I wrote a new BitTorrent tracker in Elixir alternatives
- Bubble + Blockspring alternatives
Ranked by how close each launch is in meaning, then by votes. Prices were read from each product’s own site when checked and can change. Refine with your own description →