[doc] book: big blob of changes

doc/book/about.adoc

@@ -7,40 +7,41 @@ myriads of applications. Web applications and technologies available
 to developers have evolved tremendously since the first days of the
 web.
 
-Opa is a new generation of web development platform that let you write
-distributed web applications using a single technology.  Throughout
-the pages of this book, we will introduce you to all to the many
-features of Opa. To quote but a few, Opa is concise, simple,
+Opa is a new generation of web development platform that lets you
+write distributed web applications using a single technology.
+Throughout the pages of this book, we will introduce you to the
+many features of Opa. To quote but a few, Opa is concise, simple,
 concurrent, dynamically distributed, and secure.
 
 
 What problem does Opa solve?
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-Unfortunately, the process of web application development has evolved
-neither quite as far nor nearly as fast. Indeed, developing a web
-application in 2011 is not so different from developing a PC
-application in 1991: an impressive amount of developer time is spent
-not working on features or improvements but on _gluing_ together
-antagonist technologies that were never designed to quite work
-together or in this context. In 1991, the technologies were the
-various hardware components, the low-level operating system, the
-high-level operating system and the memory itself, which could only be
-hacked into compliance through copious amounts of machine code. Per
-se, none of these technologies was wrong, but they just failed to fit
-together -- a problem now known as _impedence mismatch_.
+The web is evolving at a very fast pace. Unfortunately, the _process_
+of web application development has evolved neither quite as far, nor
+nearly as fast. Indeed, developing a web application in 2011 is not so
+different from developing a PC application in 1991: an impressive
+amount of developer time is spent not working on features or
+improvements but on _gluing_ together antagonist technologies that
+were never designed to work together or in this context. In 1991, the
+technologies were the various hardware components, the low-level
+operating system, the high-level operating system and the memory
+itself, which could only be hacked into compliance through copious
+amounts of machine code. Per se, none of these technologies was wrong,
+but they just failed to fit together -- a problem now known as
+_impedance mismatch_.
 
 Today, the technologies involved include the various incompatible
 browsers, the server components or the database components, to quote
 but a few. As in 1991, none of these technologies is wrong, but they
-do not fit together. Because of this impedence mismatch, developers
+do not fit together. Because of this impedance mismatch, developers
 need to add to their application logic copious amounts of glue code
 just to get the components to agree on communication mechanisms and
 application-level protocols. Not only is this glue code tedious,
 repetitive and error-prone, but this is also where most safety and
 security issues arise.
 
-In 1991, the answer to impedence mismatch was Software Development
+In 1991, the answer to impedance mismatch was Software Development
 Kits, and indeed these SDKs proved very useful at allowing developers
 to develop anything at all, but failed to address the underlying
 issues. This was only achieved later, through better operating
@@ -49,8 +50,8 @@ Platform, C#, Objective-C or Python, for instance.
 
 In 2011, web frameworks, both client-side and server-side, have the
 same role as the SDKs of the 1991s, with the same success but also the
-same shortcomings. But the problem remains: Building applications is
-hackish, relies on glue code and is barely reusable.
+same shortcomings. But the problem remains: Building web applications
+is hackish, relies on glue code and is barely reusable.
 
 
 How Opa solves it
@@ -67,7 +68,7 @@ Opa is a programming language and a standard library comprising a
 database management system, a web server, a server-side framework, a
 client-side framework, a distribution middleware, a security audit
 tool, but without the complexity of deployment, administration, or
-impedence mismatch stemming from the use of many different
+impedance mismatch stemming from the use of many different
 technologies.
 
 Developing with Opa is as simple as it gets: First, write your code
@@ -212,7 +213,7 @@ If you have any question or feedback, do not hesitate to contact us.
 A few ways to get in touch:
 
 - Opa https://lists.owasp.org/mailman/listinfo/opa[mailing list];
-- http://stackoverflow.com[Stack Overflow], an excellent site for seeking
+- http://stackoverflow.com/questions/tagged/opa[Stack Overflow], an excellent site for seeking
   help with programming problems (do not forget to mark Opa related questions with
   the ``Opa'' tag);
 - through http://twitter.com/opalang[Twitter], as opalang.

doc/book/asciidoc.conf

@@ -131,4 +131,4 @@ filter=source-highlight -f {backend-xhtml11?xhtml}{backend-html4?html}{backend-d
 \\<\==<=
 
 # Opa
-OPA==Opa
+OPA=Opa