There was a download of BackWeb 5.5.5895 on the developer's website when we last checked. We cannot confirm if there is a free download of this software available. The BackWeb installer is commonly called backweb.exe or Infocenter.exe etc.
BackWeb lies within Development Tools, more precisely IDE. We recommend checking the downloaded files with any free antivirus. The most popular versions of the program are 5.5, 5.0 and 2.0. This free program was originally created by BackWeb Technologies Inc.
From the developer:
A powerful multimedia development environment in which you can combine content created using Director, Shockwave, Java, Photoshop, and many other programs into presentations for broadcast on the Internet. The BALI Editor allows you to control almost every aspect of the presentations you create, so when your InfoPak downloads to a user's system, the appearance and behavior is exactly what you want.
You may want to check out more software, such as GnuWin32: LibIconv, Greatis Form Designer.Net or newObjects Active Local Pages, which might be similar to BackWeb.