Lazarus is a powerful cross platform visual integrated development environment. Based on Free Pascal, developers use Lazarus to create native code and graphical applications for the desktop operating systems, though it can also be used to create console applications and mobile apps for Android or iOS.
When you develop traditional desktop applications using Lazarus, by default you are reusing the totally platform independent Lazarus Component Library. You code your applications one time then compile against whatever platform, CPU architecture, or widget set you desire. The Lazarus bundles available on this website all include cross compile support between Windows, Macintosh, and Linux by default.
This allows you, for example, to write an application while using Macintosh then at any point compile your application for Windows while still developing on Mac. You simply copy the your application executable from Mac to Windows and it just works. There are no dependencies because Lazarus produces native code application. You write your application once, and compile anywhere.
Lazarus is also free and open source. As a matter of fact, the source code to Lazarus ships with Lazarus and you’re encouraged to modify the development environment to suit your needs. Just select “Tools | Rebuild Lazarus” from the main menu, and Lazarus will be rebuilt with any changes you've made and restart within a matter of seconds. Did we mention the speed of the Free Pascal compiler? You can even open the Lazarus project inside Lazarus, just open ‘lazarus/ide/lazarus.lpi’.
Lazarus can be used to develop commercial software without restriction. You can sell your applications without the need to pay us for anything. You do not need supply or make available your code to anyone. However, if decide to alter the compiler or make modifications to Lazarus Component Library you must make those changes available to the public and the world.