What is closed source software?

What it means

Source code is the set of instructions a programmer writes to make a program work. With closed source software, the vendor owns that code and does not publish it. You receive the finished product and a license that says how you may use it, usually for a fee.

Many widely used products are built this way, including Microsoft 365 and most vendor-supplied equipment software. The other model is open source, and plenty of businesses use both.

Why it matters to a business

• One accountable vendor: when something breaks, there is a single company responsible for the product and its fixes.
• Included support: the price usually covers documentation, updates and a way to reach the vendor's support.
• License costs: you typically pay per user, per device or per subscription, and the bill grows as your team does.
• Lock-in and dependence: the vendor sets the roadmap and the pricing, and moving away later can be hard because your data and habits are tied to the product.

How this shows up in our work

KawaConnect is an official Microsoft reseller for Microsoft 365 and Microsoft Azure, and we also work with vendor equipment that ships with its own software. Many clients use both models, for example Microsoft 365 for email and files alongside open-source infrastructure such as Proxmox. Moving virtual machines off VMware or Hyper-V, both proprietary, onto Proxmox is a common reason businesses call us.

Learn more

• Proprietary software on WikipediaA neutral definition and overview of licensing, for readers comparing the two models.
• Open Source InitiativeThe organization that stewards the Open Source Definition, helpful for understanding the alternative.