Artweaver is a freeware

Freeware

Freeware is computer software that is available for use at no cost or for an optional fee, but usually with one or more restricted usage rights. Freeware is in contrast to commercial software, which is typically sold for profit, but might be distributed for a business or commercial purpose in the...

 raster graphics editor

Raster graphics editor

A raster graphics editor is a computer program that allows users to paint and edit pictures interactively on the computer screen and save them in one of many popular “bitmap” or “raster” formats such as JPEG, PNG, GIF and TIFF....

 for Windows

Microsoft Windows

Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...

 developed by Boris Eyrich, mainly oriented to professional and amateur artists who are familiar with commercial programs like Adobe Photoshop

Adobe Photoshop

Adobe Photoshop is a graphics editing program developed and published by Adobe Systems Incorporated.Adobe's 2003 "Creative Suite" rebranding led to Adobe Photoshop 8's renaming to Adobe Photoshop CS. Thus, Adobe Photoshop CS5 is the 12th major release of Adobe Photoshop...

 and especially Corel Painter

Corel Painter

Corel Painter is a raster-based digital art application created to simulate as accurately as possible the appearance and behavior of traditional media associated with drawing, painting, and printmaking. It is intended to be used in real-time by professional digital artists as a functional creative...

. Like the latter, Artweaver is capable of simulating a wide range of classical effects (such as oil paints, acrylics, pastels, pencils, airbrushes, etc.) to create natural-looking artistic images. It also offers effect filters like sharpen, blur, emboss, and mosaic, as well as transparency and layer support in its own AWD format. Artweaver supports most common file formats, such as BMP, GIF, JPEG, PCX, TGA, TIFF, PNG, PSD, although the .BMP, .GIF, .JPEG, and .PNG formats do not have layer support. The program also has standard image editing tools like gradient, crop, fill and selection tools (including lasso and magic wand), and pen tablet support for a realistic feeling.
Artweaver can also be run in Linux

Linux

Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...

 and other Unix-like

Unix-like

A Unix-like operating system is one that behaves in a manner similar to a Unix system, while not necessarily conforming to or being certified to any version of the Single UNIX Specification....

 operating systems using Wine

Wine (software)

Wine is a free software application that aims to allow computer programs written for Microsoft Windows to run on Unix-like operating systems. Wine also provides a software library, known as Winelib, against which developers can compile Windows applications to help port them to Unix-like...

.

Starting with version 1.0 (released September 30, 2009), Artweaver is offered in two different versions: a "Free version", which can be downloaded free of charge, and the "Artweaver Plus" version, which has a cost of €25 and offers more advanced features, like compatibility with Photoshop filters and higher maximum supported image size, among others.
However, the split into two different versions implied a change in the terms of use of the "Free" version, as it now cannot be used for commercial purposes.