Does anyone know if the so called "web safe fonts" like Tahoma, Verdana, Trebuchet or Georgia are available as webfonts (that you can link to and safely use in your stylesheet) on a public CDN (content delivery network)?
These fonts might be common but they aren't guaranteedly installed on every client computer so I think it would be nice to reliably have them everywhere.
I haven't found them on Google's palette or with a search but I'm hoping that I just overlooked an obvious solution. Maybe Microsoft has a webfont CDN too only it is not quite well known yet?
The reason why they might not be legally available is licensing. Usually it's easy to just upload them in the right formats to your server and link to them trough CSS. But without a license from the copyright owner, this would be a copyright infringement.
If the rights owner does not want them to be available without payment they won't be. Users have to buy an operating system that has them or buy them separately.
You could use one of Google's fonts (or any other Font provider) as a fallback to one of this fonts. Find a font that is similar and available to use online and use it for users that don't have the main font.
If you mean for free, that's highly doubtful, at least not legally. Remember that these are not free fonts in the first place; your license fee is just built into the cost of Windows. They're available for web font licensing from Monotype's Fonts Live service. Here's Arial.
For what it's worth, the old font pack that Microsoft used to offer for free download is mirrored in a few places(eg.) It's up to you to determine whether the license allows for the kind of usage you're mentioning.