I don't think you're being fair to Chris Penner. He ends his blog post with: "It may take me another 5 years to finally finish it, but at some point we'll continue this journey and explore how we can sequence effects using the hierarchy of Category classes instead." Emphasis by me.
So while it is true, that what he has described so far is not sufficiently powerful for normal programs, he has clearly stated that there are more abstractions between Applicative and Monad to explore than what he has presented so far.
It appears Jeff Bezos has partially doxed Howard Dylan. In the email he published he removed Dylan's phone number and email address, but the image included, probably as Dylan's signature, clearly shows his phone number and email address.
Taler is free in the sense of libre software, but it is not a free payment system. In their demo they added a small transaction fee. However, because it is not a crypto currency they can greatly reduce the transaction fees.
The linked PDF also has an online version which is superior in many ways because it has inline executable Sage examples. It can be found at: http://abstract.pugetsound.edu/aata/
Also, this textbook is one of several open source textbooks developed using MathBook XML which allows authors to create multiple output formats such as PDF, HTML and ePub from one canonical source document written in XML. If you are interested in learning about MathBook XML you should check out: http://mathbook.pugetsound.edu/
So while it is true, that what he has described so far is not sufficiently powerful for normal programs, he has clearly stated that there are more abstractions between Applicative and Monad to explore than what he has presented so far.