How can I see what assemblies are installed in the global assembly cache?

No. You must copy the AjaxControlToolkit.dll assembly to the /Bin folder in your application. (More...)

.NET Framework Configuration Tool (More...)

The .NET Framework ships with a Windows shell extension for viewing the assembly cache. Navigating to % windir%\assembly with the Windows Explorer activates the viewer. (More...)

C:\$WINDOWS\assembly (More...)

Yes, provided both have different versions.
GAC is a Folder that contains .dll that have strong name. So we can keep myproject.dll and myproject.dll two files into GAC with different version like 1.0.0.0 and 1.0.0.1 (More...)

Windows SharePoint Services can use any of the following three options from ASP.NET and the CLR to provide assemblies installed in the BIN directory with sufficient permissions. The following table outlines the implications and requirements for each
option.
1.Option Pros Cons Increase the trust level for the entire virtual server.In a development environment,increasing the trust level allows you to test an assembly with increased permissions while allowing you to recompile assemblies directly into the BIN directory without resetting IIS. This option is least secure. This option affects all assemblies used by the virtual server.There is no guarantee the destination server has the required trust level. Therefore, Web Parts may not work once installed on the destination
server.
2.Create a custom policy file for your assemblies. For more information, see "How do I create acustom policy file?" Recommended approach.This option is most secure.An assembly can operate with a unique policy that meets the minimum permission
requirementsfor the assembly.By creating a custom security policy, you can ensure the destination server can run your WebParts.
3.Requires the most configuration of all three options.Install your assemblies in the GACEasy to implement.This grants Full trust to your assembly without affecting the trust level of assemblies installed inthe BIN directory.This option is less secure.Assemblies
installed in the GAC are available to all virtual servers and applications on a serverrunning Windows SharePoint Services. This could represent a potential security risk as itpotentially grants a higher level of permission to your assembly across a larger scope
thannecessaryIn a development environment, you must reset IIS every time you recompile assemblies.Licensing issues may arise due to the global availability of your assembly. (More...)

Yes you can have two or more assemblies having same name in GAC only when assemblies version no is different.As we know that all assemblies in .NET is having version no. (More...)

Assemblies which contains culture information are known as satellite assemblies. Satellite assembly is used to get language specific resources for an application. (More...)

Shared Assemblies are stored in Global Assembly Cache also known as GAC. (More...)

Assemblies are the building blocks of .NET Framework applications; they form the fundamental unit of deployment, version control, reuse, activation scoping, and security permissions. An assembly is a collection of types and resources that are built to work together and form a logical unit of functionality. An assembly provides the common language runtime with the information it needs to be aware of type implementations. To the runtime, a type does not exist outside the context of an assembly.
Assemblies are a fundamental part of programming with the .NET Framework. An assembly performs the following functions:
It contains code that the common language runtime executes. Microsoft intermediate language (MSIL) code in a portable executable (PE) file will not be executed if it does not have an associated assembly manifest. Note that each assembly can have only one entry point (that is, DllMain, WinMain, or Main).
It forms a security boundary. An assembly is the unit at which permissions are requested and granted.
It forms a type boundary. Every type's identity includes the name of the assembly in which it resides. A type called MyType loaded in the scope of one assembly is not the same as a type called MyType loaded in the scope of another assembly.
It forms a reference scope boundary. The assembly's manifest contains assembly metadata that is used for resolving types and satisfying resource requests. It specifies the types and resources that are exposed outside the assembly. The manifest also enumerates other assemblies on which it depends.
It forms a version boundary. The assembly is the smallest versionable unit in the common language runtime; all types and resources in the same assembly are versioned as a unit. The assembly's manifest describes the version dependencies you specify for any dependent assemblies.
It forms a deployment unit. When an application starts, only the assemblies that the application initially calls must be present. Other assemblies, such as localization resources or assemblies containing utility classes, can be retrieved on demand. This allows applications to be kept simple and thin when first downloaded.
It is the unit at which side-by-side execution is supported.
Assemblies can be static or dynamic. Static assemblies can include .NET Framework types (interfaces and classes), as well as resources for the assembly (bitmaps, JPEG files, resource files, and so on). Static assemblies are stored on disk in PE files. You can also use the .NET Framework to create dynamic assemblies, which are run directly from memory and are not saved to disk before execution. You can save dynamic assemblies to disk after they have executed.
There are several ways to create assemblies. You can use development tools, such as Visual Studio .NET, that you have used in the past to create .dll or .exe files. You can use tools provided in the .NET Framework SDK to create assemblies with modules created in other development environments. You can also use common language runtime APIs, such as Reflection.Emit, to create dynamic assemblies. (More...)