VS Code is free to use, but the binary Microsoft ships is not the open source project. The source is MIT licensed; the download is built under a Microsoft product licence, carries telemetry, and is the only build allowed to use the Visual Studio Marketplace. VSCodium is the same source built without branding or telemetry, and that is the whole difference in day-to-day use.
What you give up with VSCodium is real and worth knowing before you switch. It pulls extensions from Open VSX rather than Microsoft's marketplace, and several of the most useful extensions are proprietary and licensed to run only on official builds, including the C/C++ toolset, the Remote-SSH and Dev Containers pack, and the Python debugger in some configurations. If your workflow depends on remote development, stay on the official build and turn telemetry off in settings.
Against paid IDEs, Neovim with the built-in LSP client and a tree-sitter setup matches most of what a JetBrains editor does for navigation and completion, and costs you a weekend of configuration. Zed is fast and free for individual use. Helix ships language servers and multiple selections with no plugin system at all. Where JetBrains still earns its licence is deep refactoring in large Java, Kotlin and C# codebases, and the database tooling bundled into IntelliJ Ultimate.
Postman's free tier keeps shrinking around collaboration, and the app now pushes cloud sync and accounts hard. Two genuinely different replacements exist.
Bruno stores each request as a plain text .bru file inside your repository, so requests get reviewed in pull requests and diff like code, and it runs entirely offline with no account. Hurl goes further and drops the GUI: you write requests and assertions in one text file and run hurl --test api.hurl, which makes it a CI smoke-test tool as much as a client. Insomnia is still usable and has an open source core, though its account requirements have moved around across releases. Nothing free replicates Postman's team workspaces and mock servers; if that is what you are paying for, you are paying for the right thing.
DBeaver Community Edition connects to essentially every relational database through JDBC, and handles browsing, editing, ER diagrams and imports. DataGrip's advantages are a genuinely better SQL editor with schema-aware completion and refactoring, and it is a JetBrains-quality product; DBeaver CE's SQL editor is adequate rather than pleasant, and the NoSQL and cloud-warehouse drivers are the main thing held back for the paid edition. For a single Postgres database, pgAdmin or Beekeeper Studio Community is lighter than either.
Penpot is the closest thing to a real Figma alternative: open source, self-hostable, and it works in SVG and CSS natively, so what a designer builds maps onto what you implement. Figma's free tier is generous for individuals and the gap shows up in plugins, ecosystem and the sheer number of designers who already know it. Self-hosting Penpot means you own the data and the uptime.
Against Adobe, the honest pairing is per-task rather than per-suite. Inkscape genuinely competes with Illustrator for vector work. Krita is excellent for digital painting and is the better Photoshop replacement for illustration. GIMP handles photo retouching and compositing but its workflow differs enough from Photoshop that muscle memory transfers badly, and colour management for print is weaker. Darktable and RawTherapee cover Lightroom's raw development. If you need CMYK-accurate print output or team-shared Creative Cloud libraries, the free tools will fight you.
For screen recording, OBS Studio is not a compromise; it is what a large share of professionals use, and it handles multi-source scenes, capture cards and streaming. What paid tools like Camtasia give you is the editing timeline afterwards, which OBS deliberately does not have.
Caddy terminates TLS with certificates it obtains and renews from Let's Encrypt automatically, from a config file that is often three lines. That replaces the certificate-management piece people buy managed proxies for. Traefik does the same with service discovery for containers. Nginx is free too, but automatic HTTPS is the feature that makes Caddy worth the swap for small deployments.
Prometheus with Grafana replaces the metrics and dashboard half of a Datadog bill, and the part you take on is storage, retention and alert routing, which is a real operational job at scale. Uptime Kuma is a self-hosted status and uptime monitor that covers what most small teams buy Pingdom for. Umami and self-hosted Plausible cover analytics without third-party data sharing.
Three questions decide it. Does the free tool require an account or phone home, and can you turn that off in a documented setting rather than a firewall rule? Is the licence actually open source, or is it source-available with a clause preventing commercial or hosted use, which several formerly open tools have moved to? And what is the migration cost in both directions, since a tool that stores work in an open format such as Bruno's text files or Penpot's SVG lets you leave, while one that keeps everything in a proprietary cloud workspace does not. Self-hosting converts a subscription into your own time; that is a good trade for a team with an ops function and a poor one for a solo developer with a deadline.