Question:

Considering the changes of licensing of different open source projects, forcing in going in paid subscription mode to be able to continue to use the software, what would you recommend as a strategy for a small business?

Answer:

Short answer: Treat “license drift” as a normal business risk. Prefer tech that’s genuinely open and community‑governed, keep an exit plan for every critical component, and be ready to either pay for value or switch to a community fork when it’s cheaper/safer.

A practical strategy for a small business

Principles

• Favor community governance over single‑vendor control. Prefer projects under neutral foundations (Apache, CNCF, Eclipse, Linux Foundation) or with multiple independent maintainers.
• Prefer permissive, patent‑granting licenses. Bias toward Apache‑2.0, MIT, BSD, MPL‑2.0. Be cautious with “source‑available” (BSL, SSPL, Elastic License, Confluent Community License, RSAL) and strong copyleft (AGPL) if you’re a SaaS.
• Pay where it reduces risk. A modest subscription for a critical, undifferentiated component can be cheaper than migration or self‑maintaining security patches.
• Always have an exit strategy. Assume any vendor can relicense, reprice, or rate‑limit.

Immediate steps (30–60 days)
1) Inventory your stack

• Generate an SBOM for apps and infra (use Syft, CycloneDX). Include cloud services and major self‑hosted apps.
• Record: component, version, license, business criticality, who maintains it.

2) Classify license risk

• Green: Apache‑2.0, MIT, BSD, MPL‑2.0.
• Yellow: GPL/LGPL (usually fine for internal use; watch obligations when linking/redistributing).
• Red: AGPL for anything you link into proprietary code or run as part of a SaaS; source‑available (BSL/SSPL/etc.) for foundational components.
• Flag single‑vendor projects with Contributor License Agreements that allow unilateral relicensing.

3) Identify at‑risk dependencies

• Mark critical components that are single‑vendor or source‑available, or where the project recently relicensed.

4) Define an “exit hatch” per critical component
For each red/yellow:

• Option A: Budget to pay the vendor (support/subscription) for stability.
• Option B: Pin to last truly open version short‑term while you plan.
• Option C: Migrate to a community fork or open alternative.
• Option D: Buy third‑party LTS/security backports if available.

5) Add license guardrails to your dev process

• Set an “allowed licenses” policy in CI (Snyk, FOSSA, Black Duck, OWASP Dependency‑Track or OSV-Scanner + custom rules).
• Turn on license alerts in Dependabot/Renovate and require approval for red licenses.
• Keep NOTICE/attribution files and comply with obligations.

Medium term (1–3 quarters)

• Architecture for replaceability
• Use open standards and portable data formats. Avoid deep use of vendor‑exclusive features unless it’s strategic.
• Add abstraction layers (ORM for DBs, S3‑compatible storage APIs, standard protocols).
• Containerize and codify infra (IaC) so you can redeploy elsewhere quickly.
• Procurement and contracts
• For paid software/services: require advance notice on material license or pricing changes, capped renewal increases, data export guarantees, and clear SLAs.
• For critical SaaS: verify data portability and run periodic restore/migration drills.
• Monitoring and governance
• Assign an owner (even part‑time) to watch license changes, project health, and release notes.
• Review the SBOM quarterly; re‑score risk and update plans.
• Support the ecosystem
• Consider small sponsorships or Tidelift for components you rely on to improve sustainability and response to CVEs.

When choosing or replacing components

• Databases: Prefer PostgreSQL, MariaDB/MySQL community for greenfield. If you rely on MongoDB features, weigh the cost of Atlas/support vs. migrating; alternatives include PostgreSQL JSONB or FerretDB (Mongo wire‑compat on Postgres).
• Search: If you’re concerned about Elastic’s licensing, consider OpenSearch (community fork).
• Caching: If Redis’s licensing is an issue for you, consider Valkey (Linux Foundation fork) or ensure your usage is compliant and budget support.
• IaC and secrets: Terraform (BSL) → OpenTofu (MPL‑2.0). Vault (BSL) → consider OpenBao (MPL‑2.0) if it meets your needs.
• Observability: Prometheus (Apache‑2.0); Grafana and related projects are AGPL—fine to use as separate services, but avoid linking AGPL code into proprietary products.
• Streaming: Apache Kafka core is Apache‑2.0; Confluent adds components under a community license—know the boundary.

Notes on AGPL and SaaS

• Using an AGPL application unmodified as a separate service is generally fine; if you modify it, you must publish your modifications.
• Do not link AGPL libraries into proprietary code unless you’re willing to open source your code under AGPL.

Cost/risk decision framework

• If the component is mission‑critical and migration cost is high: prefer paying for support/subscription with protective contract terms.
• If there’s a healthy, foundation‑backed alternative or fork: pilot migration and plan a phased cutover.
• If you pin to an older open version: ensure you have a security plan (backports, WAF, isolation) and a time‑boxed path off the fork.

Operational tips

• Keep regular, tested backups in open formats and documented runbooks for restoring to alternative stacks.
• Track CVEs for pinned components; subscribe to security advisories.
• Maintain version and license pins in manifests to avoid surprise upgrades.

This is not legal advice. For any gray areas (especially AGPL, SaaS distribution, or source‑available terms), consult counsel.