This article is based on an ongoing, decision-oriented comparison between Delphi and Free Pascal/Lazarus, maintained as a public reference on GitHub, with feedback encouraged:
https://github.com/ideasawakened/delphi-and-fpc-lazarus-comparison
What follows is a guided walk-through of the comparison, highlighting the most important decision points rather than reproducing the full tables. This article serves as a partial reference and overview - the complete, up-to-date comparison lives in the public GitHub repository. The discussion focuses on project fit, workflow friction, CI/CD realities, licensing and compliance considerations, and long-term maintenance risk.
If you are evaluating Delphi, Free Pascal/Lazarus, or both, this repo is intended to help you decide which tool is the better fit for a given scenario, and just as importantly, why.
TL;DR
- Choose Delphi when productivity, tooling depth, and commercial support matter most.
- Choose Free Pascal / Lazarus when open tooling, licensing flexibility, and CI friendliness are primary concerns.
- In many cases, both are viable, and the deciding factor is workflow friction rather than raw capability.
Comparison Highlights
Delphi and Free Pascal/Lazarus occupy a unique space in the programming landscape.
- They share a common Pascal heritage
- Many developers actively use both
- Both are capable of producing fast, native code
- Both are used in long-lived production systems
For years, comparisons between Delphi and Free Pascal/Lazarus have tended to fall into one of two categories:
- Feature checklists that miss the real decision points
- Ideological debates that generate more heat than clarity
Rather than asking “Which language is better?”, it asks a more practical question:
“Given this kind of project and these constraints, which tool is the better fit?”
The result is a decision-oriented comparison designed for experienced developers, architects, and technical leads who may already use (or have used) both.
Section A - Quick Decision Matrix
The document opens with a simple decision matrix. This is intentional as most developers do not want to read 30 pages before understanding whether a tool is even relevant to their situation.
Some representative examples:
Commercial Windows desktop applications
Delphi is strongly recommended due to tooling depth, UI frameworks, and ecosystem maturity.
Free Pascal/Lazarus is viable, but often requires more manual integration and testing.Cross-platform open-source tools
Free Pascal/Lazarus is strongly recommended due to licensing flexibility and CI friendliness.
Delphi is viable, but introduces additional workflow complexity in open CI environments.Embedded or bare-metal targets
Free Pascal/Lazarus has real advantages here. Delphi is not designed for this class of deployment.
Section B - Feature Comparison by Developer Intent
Rather than grouping features by category (language, IDE, RTL), the comparison is organized around what developers are trying to accomplish.
Examples include:
- Tooling and IDE experience
- UI frameworks and visual design workflows
- Platform and deployment targets
- Ecosystem and third-party libraries
- Licensing, cost, and compliance considerations
One recurring theme in this section is friction.
In many cases, both Delphi and Free Pascal can achieve the same technical outcome. The difference is often how much setup, integration, and ongoing maintenance is required to get there.
Section C - Pick This If… Decision Guides
This is where the comparison becomes most practical.
Instead of abstract trade-offs, Section C answers common questions directly:
- Pick Delphi if you are building a commercial Windows desktop application with a rich native UI.
- Pick Free Pascal/Lazarus if you need fully open tooling with minimal licensing friction.
- Either tool may be appropriate if you are building shared native libraries or backend services and already have strong internal expertise.
This section is designed to be shareable and quotable. It reframes the discussion from better vs worse to fit for purpose.
Section D - CI/CD, Automation, and Workflow Realities
This section tends to generate the most discussion, and intentionally so.
Modern development workflows rely heavily on automation, hosted CI, and reproducible builds. Delphi and Free Pascal approach this very differently.
- Free Pascal integrates naturally with hosted CI platforms and standard build runners.
- Delphi often requires local or self-hosted runners due to licensing constraints.
Neither approach is inherently wrong, but the operational impact is real and should be acknowledged openly.
Section E - Compliance and Supply Chain Considerations
Compliance, SBOMs, and supply-chain risk are increasingly important topics.
This section does not attempt to audit either ecosystem, but it does highlight structural differences:
- Centralized commercial tooling versus decentralized open-source ecosystems
- Responsibility boundaries when vulnerabilities arise
- Packaging and distribution implications
The goal is not to alarm, but to encourage informed risk assessment.
Appendix - Common Misconceptions
The document closes by addressing common claims that tend to derail productive discussion, including:
- “Free Pascal / Lazarus is just a Delphi clone”
- “Delphi is Windows-only”
These are addressed factually and without rhetoric.
This is a living document
This comparison is not intended to be final or authoritative.
If you have:
- Corrections or factual errors
- Missing scenarios or use cases
- Supporting documentation or benchmarks
- Real-world experience that contradicts or reinforces a claim
- Links to official documentation that improve accuracy
Please contribute.
Issues, pull requests, and links are all welcome.
The goal is not to win an argument, but to build a reference that experienced developers can point to when the Delphi vs Free Pascal/Lazarus question inevitably comes up.
Read it, challenge it, improve it
If you use Delphi, Free Pascal/Lazarus, or both, your perspective is valuable. The best comparisons are not written once as they are refined over time. Please Star the repository on GitHub to show your support, and Watch the repo so you do not miss community contributions.
https://github.com/ideasawakened/delphi-and-fpc-lazarus-comparison