Lazarus is a free cross-platform visual integrated development environment (IDE) for rapid application development (RAD) using the Free Pascal compiler.
Software developers use Lazarus to create native-code console and graphical user interface (GUI) applications for the desktop, and also for mobile devices, web applications, web services, visual components and function libraries for a number of different platforms, including Mac, Linux and Windows.
An application created using Lazarus on one platform can generally compile and execute on any platform for which a Free Pascal compiler exists. For desktop applications a single source can target Mac, Linux, and Windows, with little or no modification. An example is the Lazarus IDE itself, created from a single code base and available on all major platforms including the Raspberry PI.
Video Lazarus (IDE)
Features
Lazarus provides a highly visual development environment for the creation of rich user interfaces, application logic, and other supporting code artifacts, similar to Borland Delphi. Along with project management features, the Lazarus IDE also provides:
- A What You See Is What You Get (WYSIWYG) visual windows layout designer
- GUI widgets or visual components such as edit boxes, buttons, dialogs, menus, etc.
- Non-visual components for common behaviors such as persistence of application settings
- Data-connectivity components for MySQL, PostgreSQL, FireBird, Oracle, SQLite, Sybase, and others
- Data-aware widget set that allows the developer to see data in visual components in the designer to assist with development
- Interactive code debugger
- Code completion
- Code templates
- Syntax highlighting
- Context-sensitive help
- Text resource manager for internationalisation (internationalization)
- Automatic code formatting
- The ability to create custom components
Maps Lazarus (IDE)
Cross-platform development
Lazarus uses Free Pascal as its back-end compiler. Therefore, Lazarus can theoretically be used to develop applications for all platforms supported by Free Pascal.
Lazarus provides a cross-platform application framework called the Lazarus Component Library (LCL), which provides a single, unified interface for programmers, with different platform-specific implementations. Using LCL, it is possible to create applications in a write once, compile anywhere manner, unless system-dependent features are used explicitly.
Cross-compiling
As Free Pascal supports cross-compiling, Lazarus applications can be cross-compiled from Windows to Linux and FreeBSD, and vice versa. Compiling from macOS to Windows, Linux and FreeBSD is possible. Cross-compiling to macOS could be done for older (PowerPC) versions, but not for newer Intel versions, since Apple no longer releases the assembler and linker sources.
Applications for embedded devices (smartphones, PDAs, routers, game consoles) are cross-compiled from a *nix or Windows.
Android applications can be generated from Lazarus 1.4.
Lazarus Component Library
The standard application framework, Lazarus Component Library (LCL) was modeled after the Visual Component Library (VCL) in Delphi 6, and, unlike Delphi, is not restricted to Microsoft Windows operating systems. This is done by separating the definition of common widget classes and their widgetset-specific implementation. Each widget set is supported by providing an interface which interacts directly with the set.
Database development
Developers can install packages that allow Lazarus to support several database management systems (DBMSes). Programs can interact with DBMSes through code or by components dropped on a form.
The following DBMSes are supported out of the box:
- dBase and FoxPro, supported through the TDbf component
- InterBase / Firebird. See [1]
- Microsoft SQL Server and Sybase ASE. See [2]
- MySQL and MariaDB. See [3]
- ODBC databases. See [4]
- Oracle. See [5]
- PostgreSQL. See [6]
- SQLite. See [7]
- Simple, local, flat file databases through TBufDataset, TMemDataset and TSdfDataset.
Differences from Delphi
While resembling Delphi in many ways, there are a few limitations regarding the performance and feature set, including:
- Under Windows the default size of an executable file is larger than the Delphi 6 or Delphi 7 equivalent as Lazarus stores debug information within the executable rather than as separate files. From release 0.9.30 Lazarus supports external debug symbols; program file size can be significantly reduced by using an external symbols file (it can be set in Compiler options), or by using Strip
- Components for Delphi can be installed in Lazarus, but they must be converted, which can be complex (less complex since FP 2.4.x-based 0.9.30)
- Missing important media libraries and widgets:
- Microsoft Office connectivity before FPC 2.6.0 release. Popping up Excel with a simple table filled out in 2.6.0 and higher works.
- Datasnap (not a publicly documented system, Embarcadero proprietary enterprise functionality)
- Networking is mostly available
- No support to directly call .NET libraries;. It is possible to call Object Pascal code from .NET software.
- COM support was missing until version 2.2.0.
- Missing dynamically loadable packages support.
- Not 100 percent compatible with VCL. As mentioned previously this is by design, although the current LCL widget set should suffice for most applications. But this makes the deep repository of available VCL widgets inaccessible without conversion. The conversion effort mostly involves some editing, although there are a few fundamental differences. When porting, missing units in the libraries and COM support are a considerably bigger problem than incompatibilities between LCL and VCL.
Distribution and licensing
Like Free Pascal, Lazarus is free software. Different portions are distributed under different free software licenses, including GPL, LGPL, MPL, and a modified version of LGPL.
Specifically, the LCL, which is statically built into the produced executables, is licensed under a modified version of the LGPL, granting extra permissions to allow it to be statically built into the produced software, including proprietary ones.
Installing a design-time package is equivalent to linking to the IDE, thus distributing the Lazarus IDE with a GPL-incompatible design-time package (e.g. the JEDI packages, which are licensed under the Mozilla Public License) pre-installed would cause a license violation. This however does not prohibit proprietary packages from being developed with Lazarus.
Lazarus is officially distributed via Sourceforge.
History
The first attempt to develop a visual IDE for Free Pascal dates back to 1998, when the Megido project commenced. For various reasons this approach failed. Some of Megido's developers then started a new project based on a more flexible foundation.
The first preliminary LCL version was ready for release in 2001, and in 2003 the first beta version of Lazarus (0.9.0.3) was hosted at SourceForge. The first final Lazarus version (1.0) was released in 2012, and significantly enhanced Lazarus 1.2 with was released in 2014. More than four million downloads had been made from SourceForge as of March 2014.
The name "Lazarus" alludes to the revival of the Megido concept. It is inspired by Lazarus of Bethany, who, according to the Gospel of John, was restored to life by Jesus four days after his death.
Versions
Applications produced with Lazarus
- ASuite is a free open source application launcher for Windows. From 2.0 Alpha 2, it's fully written in Lazarus/FPC.
- Beyond Compare is a data comparison utility for Windows, macOS, and Linux. The macOS and Linux versions are compiled using Lazarus/FPC.
- Cartes du Ciel is a free planetarium program for Linux, macOS and Windows. The software maps out and labels most of the constellations, planets, and objects you can see with a telescope. It is fully written in Lazarus/FPC and released under GPL.
- Cheat Engine is an open source memory scanner/hex editor/debugger. It is useful for cheating in computer games. Since version 6.0 it is compiled with Lazarus/FPC.
- EPANET, a software package for modelling water distribution systems.
- HNSKY, Hallo Northern Sky is a free planetarium program for Windows and Linux. Since version 3.4.0 written & compiled with Lazarus/FPC.
- MyNotex is a free software for Gnu/Linux useful to take and to manage textual notes.
- Peazip is an open source archiver, made with Lazarus/FPC.
- TorChat is moving away from Python, and is being rewritten in Lazarus + Free Pascal.
- Total Commander 64-bit version.
- Double Commander is a cross platform open source file manager with two panels side by side. It is inspired by Total Commander and features some new ideas.
Libraries compatible with Lazarus
- GLScene is a free OpenGL-based library that provides visual components and objects allowing description and rendering of 3D scenes.
- OpenWire is an Open Source library that allows pin type properties to make connections between LCL components similar to LabVIEW or Agilent VEE.
See also
- Free Pascal Compiler
- Dev-Pascal
- Comparison of Pascal IDEs
- Embarcadero Delphi
- Object Pascal
![СообÑеÑÑво Free Pascal / Lazarus IDE [RUS] - YouTube](https://lh3.googleusercontent.com/blogger_img_proxy/AEn0k_uuMF1ynnCOFIoNqojirJne0M_grv-yT8fuZy236DWqlHufHSLuoUWue4TbsDoyPUftnC3vxnveP7JNZn4nI6ZCmHFc5FV98nbvubzR-KI_GwxsBhzPNIbyrzzvl7XTuth_Wgiy6wOP=s0-d "СообÑеÑÑво Free Pascal / Lazarus IDE [RUS] - YouTube")
References
Additional references
- Michaël van Canneyt; Florian Klämpfl (2012), Free Pascal (Free Pascal 2 ed.), Computer & Literatur Verlag GmbH, ISBN 978-3936546729, 393654672X
- Michaël van Canneyt; Mattias Gärtner; Swen Heinig; Felipe Monteiro de Carvalho; Inoussa Ouedraogo; Jörg Braun (2011), Lazarus, Böblingen, Germany: Computer & Literatur Verlag GmbH
- Michaël van Canneyt; Mathias Gärtner; Swen Heinig; Felipe Monteiro de Carvalho; Inoussa Ouedraogo (2011), Lazarus - the complete guide, Blaise Pascal Magazine
External links
- Lazarus Homepage
- About Lazarus
- Project Homepage at SourceForge.net
- The Lazarus Documentation Project
- Get Lazarus hosting downloads
- Lazarus learning center
Source of article : Wikipedia
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