Is It Web $1\mathrm{.}0$ or Web $2\mathrm{.}0?$

Deciding whether a given site is Web $1\mathrm{.}0$ or Web $2\mathrm{.}0$ is not as straightforward as it appears. Websites do not have version numbers, and many are dynamic enough to be in permanent beta testing. Facebook and MySpace are good Web $2\mathrm{.}0$ examples, primarily due to their social networking functions and their reliance on user$-$generated content. Some sites are easy to identify as Web $1\mathrm{.}0$ in their approach: Craigslist, for example, emulates an email list server and has no public user profiles or dynamic pages. Many other sites are hard to categorize.

Amazon.com launched in the mid$-1990$s and has gradually added features over time. The principal content $($product descriptions$)$ is not user$-$created, but much of the site's value is added by user reviews and ratings. Profiles of users do exist, but social features such as friend links, although present, are not widely ackopted.

Review the following websites and categorize them as Web $1\mathrm{.}0,$ Web $2\mathrm{.}0,$ or both. Be sure to justify your answer with the characteristics that classify the website as $1\mathrm{.}0,2\mathrm{.}0,$ or both. Why would certain types of businesses choose to remain Web $1\mathrm{.}0$ and not offer collaboration or open source capabilities?