JustDecompile

JustDecompile is a handy free software tool that is used for decompiling .NET assemblies. It allows developers to quickly recover lost source or examine assemblies to find the root cause of an external bug. Its decompilation engine is open source under the Apache 2.0 license, while the user interface is not. The program offered auto-update support, but it was retired in April 2024 and no longer receives updates. 

JustDecompile is also a good tool that can be used to create a Visual Studio project from a decompiled assembly. It can also be used to extract resources embedded in assemblies, and it offers features that enable users to quickly locate and navigate to different parts of code. All the loaded assemblies can be browsed by type, method, or members. The search function embedded inside the software updates dynamically as you type in your search queries. The other benefit of JustDecompile is it can one-click load all system libraries for each framework. Users can also create a custom assembly list and load them with one single click of the mouse button. It is compatible with different runtime environments, languages, and technologies, such as .NET 2, 3.5, 4, 4.5, 4.5.1, Silverlight and APPX, WinRT, Winmd, C#, VB.NET, MSIL.

In addition, JustDecompile offers the user the ability to add as many assemblies as one wants using the drag and drop feature. The "Assembly List" menu enables users to load all existing assemblies in one location, as well as create new ones. On top of the aforementioned features, JustDecompile allows users to preview the code, used resources, values, and objects for each assembly. Various plug-ins, such as the de4dot deobfuscation extension, extend the utility of this program even further. 

JustDecompile is a program that was developed by Telerik, a Bulgarian company that was founded in 2002. Telerik was later acquired by Progress Software.  Since the retirement, no new downloads are offered on the official site and technical support has ended. Progress recommends the free ILSpy and dotPeek decompilers as alternatives, while users who already have JustDecompile can continue to use it.

JustDecompile offers a fast search for quickly locating types and members, and it supports multiple .NET runtimes and languages.

Features:

• Decompiles assemblies to C#, VB.NET and IL code
• Provides an open API for everyone to create extensions
• Supports multiple runtime environments, languages, and technologies: .NET 2, 3.5, 4, 4.5, 4.5.1, Silverlight and XAP, APPX, WinRT, Winmd, C#, VB.NET, MSIL
• Fast navigation combined with a quick search to find types and members  
• Integration within Windows Explorer for fast browsing and decompiling
• Able to generate projects from the command prompt directly.