aspNetMHT is a .NET component (dll) used for building and compiling MHT documents. MHT is short for MHTML. aspNetMHT can be used in any application written in .NET 1.0 and above. It is a component, or assembly, that does not have a GUI. It can only be accessed and used programmatically from .NET aspNetMHT is meant to be used by developers to build applications that support the MHT archival techniques.

So what exactly is MHT?
MHT is short for MHTML, which stands for Mime (formatted) HTML. The idea behind MHT documents is to embed all external resources, usually images, in a single document. You can think of MHTML as a HTML document with all external images, frames, etc.. embedded in the document, not just linked from the document. This allows for the document to be viewed at a later date, in it's entirety, without broken links. MHT is an internet standard, RFC #2557, and has been around since 1999. MHT was made popular when IE 5 added it to the File | Save As menu option, allowing HTML pages to be saved as type "Web Archive, single file (*.mht)".

MHT documents links to internal resources, or parts, through the use of the Content-ID or Content-Location headers. Each internal resource is considered a part, and will have it's own set of headers. The Content-ID header is an identification header that is unique to the document. The Content-Location header is a URI for the respective part. A part can be referred to by either of these headers.

The following diagram graphically shows the architecture of the MHT Document.

The parent MHT document is also happens to be a MHT object in aspNetMHT. The MHT object inherits from a MHTPart. Each parent MHT can have one or more MHTParts as children. When this object is rendered, by calling MHT.ToString(), the following equivalent text is output:

From:<Saved by aspNetMHT>
Subject: MHT Document
Content-Type: multipart/related; boundary="boundary-example";
type="text/html"

--boundary-example

Content-Type: text/html; charset="US-ASCII"

This is the body of my MHT document. It contains 2 images
<IMG SRC="fiction1/fiction2"> 
... ...
<IMG SRC="cid:97116092811xyz@foo.bar.net"> 

The SRC values for these images 
actually point to references found inside of this document. 

--boundary-example
Content-Type: image/gif
Content-Location: fiction1/fiction2

R0lGODlhGAGgAPEAAP////
ZRaCgoAAAACH+PUNvcHlyaWdod
CAoQykgMTk...etc...

--boundary-example
Content-Type: image/gif
Content-ID: <97116092811xyz@foo.bar.net>

NSBJRVRGLiBVbmF1dGhv
cml6ZWQgZHVwbGljYXRpb
24gcHJvaGliaXRlZC4A
etc......
--boundary-example—
	

What can I use to view MHT documents?
MHT documents can be viewed in both IE and Firefox. For IE users, version 5.0 and greater can be used. For Firefox users, a MHT plugin is required from http://maf.mozdev.org

So what does aspNetMHT do?
aspNetMHT is a .NET component (.dll) written in C#, and requires the Microsoft .NET framework to run. It is used to programmatically build MHT documents. aspNetMHT can automatically build MHT files from Urls, HTML strings, files, and ASP.NET server controls. aspNetMHT will parse the rendered HTML for external references and embed them into the single MHT document.

Can I use aspNetMHT in windows applications?
Absolutely! Since aspNetMHT was written in C#, it will run in any .NET environment or application. You can use aspNetMHT in a Windows Form application, web services, ASP.NET web pages, and any other .NET supported application.