This is a deck to help teachers learn some web technology concepts at a show about social technology tools in education.

1. Technology for Teachers
By Ed Lyons
Social Technology in Education
Conference
8 / 14 / 2009

2. Agenda
How much technology should teachers know?
The Internet: Clients and Servers
Operating Systems: Windows, UNIX, Linux
Applications: Platforms and Languages
All About Open Source
Browsers and Extensions
The Tech Behind “Web 2.0”: Services, APIs, Mashups,
OpenID, OAuth, AJAX, DHTML, Flex

3. About this material
The point of this presentation is to help
teachers understand important concepts.
This content is not meant to be a
comprehensive treatment of the topics.
Some things will be simplified to the point
that computer scientists would find the
explanations lacking or even inaccurate.
In addition, the author of this presentation
has strong opinions about these topics, which
will color the content.

4. How much tech should
teachers know?
Technology is very complicated. However, if
teachers want to experiment with social
tech, it would help to know some basics.
What has changed recently is that more can
be accomplished with a small amount of
knowledge than ever before.
The right kinds of knowledge will allow a
teacher to deploy web tech without IT help!

5. The Internet:
Clients and Servers
Every machine on the Internet is identified
by a four-number code, such as 64.2.44.22
Computers have “ports” to direct traffic
inside it (kind of like apartment numbers for
a building) If you don’t specify a port (in
web usage) it assumes you mean port 80.
There is also a system of names for most of
those machines to help people remember
them: www.nytimes.com, etc.

6. The Internet:
Clients and Servers
Computers can play two roles: they can
either be “servers” (where they provide info)
or “clients,” where they ask for information.
If you want to set up something for people
to use, you’ll need a “server.”
That used to mean you’d need to buy/borrow
a physical machine to sit somewhere near
you. Now, you can rent powerful machines in
just minutes for very little money.

7. Why all this matters:
With no technical knowledge, you can go to a
site, spend $10, and you will have your own
rented server at an address like:
124.44.201.109 You can then get a name: visit
a site, buy it ($10) and then type
124.44.201.109 into a form. (20 mins total)
When someone says “Try this experimental
site: http://55.23.200.11:3000/network” you’ll
know: that’s a server he uses where he didn’t
buy a name and he’s not using port 80
because he isn’t the owner of that machine
(port 80 can only be used by server owners)

8. Operating Systems
The operating system is the software that
connects applications with the hardware.
For our purposes, there are two kinds of
operating systems: free and commercial.
Examples of commercial: Windows, Macintosh
Examples of free: UNIX (BSD, OpenSolaris)
and Linux (Ubuntu, Fedora, CentOS)
Most of you use Windows every day. All of
you that have Tivo also use Linux every day.

9. Operating Systems
Virtually all rentable servers use the free
operating systems. (Cheap ones are all free)
Unless you have an application that must run
on a paid system, there is no point in using
that on a server. (Which is why Facebook,
Twitter, et al all use the free ones)
Ultimately, what operating system you use
should have no impact on your application.
However, if you are going to be doing
administration on a server, you need to have
someone who can handle using that system.

10. Applications: Platforms
When someone wants to create a web
application, they need to decide what
components they will use. Techies call this
“the stack”. Someone once asked me, “What’s
the stack for the BPS site?” (Answer:
OpenSolaris, MySQL, Apache, PHP, Drupal)
Many web applications use a version of the
LAMP stack: Linux, Apache, MySQL, PHP
This matters when you have an application
and need a server. The server must support
the stack your application needs.

11. Applications: Languages
Java, C#, C++, VB, JavaScript, Perl, Python,
Ruby, PHP, Erlang, Lisp, and hundreds more!
Two categories: general-purpose (Java, C#)
and “scripting” (PHP, Ruby, PHP, Python).
Most new “Web 2.0” apps use the latter.
Twitter uses Ruby; Facebook, Elgg, Wikipedia
use PHP. It is faster and easier to use the
scripting languages to develop web apps.
If you want to change an app, you need
someone who knows that language.

12. About Open Source
One of the most important things to
understand is the free software movement,
which is a copyright reform project that
started 20 years ago.
Basically, many thousands of volunteers have
created a “public commons” for software,
letting anyone use this software without
charge. It has dramatically changed the
software world and is one of the most
important collaborative efforts ever!

13. About Open Source
There are lots of kinds of free software
licenses: some require you to give changes
back to the community, others do not.
Commercial firms have spread fear for years
about the “dangers” of these licenses. After
20 years, there is no reason to be afraid.
Because these public domain projects can
accept small contributions from all over the
world, there is a great deal of innovation
going on within them.

14. About Open Source
Designating an application “open source” (like
Elgg) means that anyone can use it, and, if it
is a certain type of license (GPL) people must
give back any changes they make.
This has an interesting effect on business
models, who decides to use it, and how users
perceive that application.

15. About Open Source
Open Source is often favored by government
and civic-minded organizations because it is:
Free
Trustworthy (anyone can audit the code)
Able to be modified in any way.
You are not beholden to a for-profit
company that may not share your values.

16. Browsers and Extensions
For the most part, internet browsers all do
the same thing: render web pages and host
small applications.
Like operating systems, there are free and
non-free browsers.
Free: Firefox, Chrome
Non-free: Internet Explorer, Safari

17. Does it matter what I use?
Probably not, but....
Internet Explorer has been the least
innovative, most insecure browser for years.
Firefox has hundreds of useful extensions
that modify how it works and what it does.
It is good for the health of the technology
ecosystem to use a browser that
meaningfully supports industry standards, 70
languages, and an open web. Only Firefox
does that.

18. Tech of Web 2.0
Services, APIs, Mashups
One of the things that had made the web
very dynamic is the creation and consumption
of publicly-available services.
A service is a feed of data that takes input
parameters, and provides a data set as a
response. (In the earlier days of the web,
servers only rendered pages of data with
formatting, content, images together)
Data format examples: RSS, ATOM, JSON

19. Tech of Web 2.0
Services, APIs, Mashups
An API (Application Programming Interface)
is just the set of services that a an app
offers to get data in and out, or change what
it does. APIs aren’t necessarily web-related.
Lately, people have published services that
anyone can use. When these services are
consumed and combined into a new web
application, that’s called a “mashup”
Important: services are usually consumed by
machines. (People use web browsers.)

20. Tech of Web 2.0
Services, APIs, Mashups
So, you can now say cool things like:
“We could just take the list of classes we offer, expose it
as a service using JSON, and let people do whatever they
want with it.”
“People can post their photos of the event to Flickr using
the tag we choose, and we could use their API to pull the
pictures from there!”
“We could just use the OAuth service in Twitter to let
students automatically create accounts in our network.”

21. Tech of Web 2.0
OpenID, OAuth
• OpenID is a mechanism that let’s you have one
username on lots of websites. You can then
designate a site where you enter the same
password for everything. The key is that your
single password lives on that server, and you
can use it anywhere. Many sites support this.
• OAuth is different, but very useful. It is a way
that someone can grant their account
information to someone else in a very limited
way, without giving that site your password.

22. Tech of Web 2.0
AJAX, DHTML, Flex
• AJAX is a way that the web page you’re
looking at can talk to a server to get/receive
data without you doing anything.
• Dynamic HTML (DHTML) is a way to provide
visual special effects on your web page.
• Flex is the name of the component framework
from the Flash people - known more for
showing movies and animations on sites. Flex
sites feel less like a web page of text and
more like a movie or desktop application.

23. Summary
The web is a network where client machines find server
machines using their addresses and ports to access the
applications that live on certain operating systems and use
particular stacks (that are almost always open source these
days) that make data available either as web pages for
browsers or services for programs living on other servers.
Perhaps that service might even get used by some PHP
developer who, wanting to create an app on an OpenSolaris
server he rented, will combine that with three other public
services to create a mashup that uses AJAX and DHTML
(because he never learned Flex) for real-time updates, and
lets people create accounts on his site using OpenID, and uses
OAuth to pick up their Twitter profile photo and use it there.