Webspider 0.1 for Mac was available to download from the developer's website when we last checked. We cannot confirm if there is a free download of this app available. The software lies within Developer Tools, more precisely Webmaster Tools. We recommend checking the downloaded files with any free antivirus. This free Mac app is an intellectual property of johnny194.
From the developer:
WebSpider is a program that provides a mechanism to get contents from the Web. With the extended classes, you can grab URLs from a specified base URL, analyze the contents of a list of URLs, and get specific files from web sites. Also it is an Internet bot that systematically browses the WWW, typically for the purpose of Web indexing.
You may want to check out more software for Mac, such as MacCVSClient X, AcidSearch Installer or AlbumEnabler, which might be related to Webspider.