This is an overview providing 10 Linux open-source replacements for various commercial power tools, most of them available only on Windows.

Computer-Aided Design: AutoCAD
Replacement: QCAD
It’s true, QCAD has some paid plug-ins, but they can be removed very easy and QCAD will offer most of AutoCAD’s features in a similar fashion, but with an interface that is maybe 10 times faster. The good thing about QCAD is that those who are used to AutoCAD can make the transition pretty easily, since QCAD has similar syntax for commands, and similar menu entries.

Image Editor: Photoshop
Replacements: GIMP and Krita
Both GIMP and Krita are powerful image manipulation tools, the first one being written in GTK, while Krita integrates better in KDE. These applications comes with support for layers, powerful editing tools, saving or exporting to a huge number of formats, visual effects, filters. Lately Krita is getting a lot of attention, with new releases on a regular basis and work to include it in Steam as a free download.

Office Suite – MS Office
Replacement: LibreOffice
LibreOffice is the powerful office suite included in all the big distributions out there. It comes with word processor, presentation and spreadsheet applications. If you want something for KDE, you can try Calligra Suite as well.

Partitioning – Partition Magic
Replacement: GParted
A powerful partitioning tool, GParted helps you create new partitions or resize existing ones.

Virtualization Software – VMWare Workstation
Replacement: QEMU
QEMU is a free virtualization application which allows you to try various operating systems in your running environment, without the need to reboot the computer.

Geographic Information System – ArcGIS
Replacement: QGIS
QGIS is a decent replacement to the geographic application ArcGIS.

(Image credit)

Email Client – MS Outlook
Replacement: Thunderbird
Thunderbird is a feature-rich email application developed by Mozilla.

3D Graphics – 3ds Max
Replacement: Blender
Blender is a free, powerful 3D modeling application with lots of features, which was used to create some sound projects, including Big Buck Bunny.

Web Browser – Internet Explorer
Replacement: Firefox
Firefox is the popular web browser, with a very powerful, modern web rendering engine, support for tabs, add-ons, themes, developer tools, plug-ins, powerful address bar, history management and not only.

CD/DVD Burning Application – Nero
Replacement: K3b
K3b is a good CD/DVD burner and ISO image creator, which fits well in KDE.