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+@c Update all node entries with `C-c C-u C-n'.
+@c Insert new nodes with `C-c C-c n'.
+
@menu
-* Introduction:: About 8sync
+* Introduction::
+* Acknowledgements::
* Copying This Manual::
-* Index:: Complete index.
+* Index::
@end menu
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-
@node Introduction
@chapter Introduction
-8sync 8sync 8sync!
+8sync's goal is to make asynchronous programming easy.
+If you've worked with most other asynchronous programming environments,
+ you know that it generally isn't.
+Usually asynchronous programming involves entering some sort of
+ ``callback hell''.
+Some nicer environments like Asyncio for Python provide generator-based
+ coroutines, but even these require a lot of work to carefully line up.
+
+Coding in 8sync, on the other hand, looks almost entirely like coding
+ anywhere else.
+This is because 8sync makes great use of a cool feature in Guile called
+ ``delimited continuations'' to power natural-feeling coroutines.
+Because of this, you can invoke your asynchronous code with a small wrapper
+ around it, and that code will pop off to complete whatever other task it
+ needs to do, and resume your function when it's ready passing back the
+ appropriate value.
+(No need to manually chain the coroutines together, and no callback hell at
+ all!)
+
+Now that's pretty cool!
+
+@node Acknowledgements
+@chapter Acknowledgements
+
+8sync has a number of inspirations:
+
+@itemize @bullet
+@item
+@uref{https://docs.python.org/3.5/library/asyncio.html, asyncio}
+ for Python provides a nice asynchronous programming environment, and
+ makes great use of generator-style coroutines.
+It's a bit more difficult to work with than 8sync (or so thinks the author)
+ because you have to ``line up'' the coroutines.
+
+@item
+@uref{http://dthompson.us/pages/software/sly.html, Sly}
+ by David Thompson is an awesome functional reactive game programming
+ library for Guile.
+If you want to write graphical games, Sly is almost certainly a better choice
+ than 8sync.
+Thanks to David for being very patient in explaining tough concepts;
+ experience on hacking Sly greatly informed 8sync's development.
+(Check out Sly, it rocks!)
+
+@item
+Reading @uref{https://mitpress.mit.edu/sicp/, SICP}, particularly
+ @uref{https://mitpress.mit.edu/sicp/full-text/book/book-Z-H-19.html#%_chap_3,
+ Chapter 3's writings on concurrent systems},
+ greatly informed 8sync's design.
+
+@item
+Finally, @uref{https://docs.python.org/3.5/library/asyncio.html, XUDD}
+ was an earlier ``research project'' that preceeded 8sync.
+It attempted to bring an actor model system to Python.
+However, the author eventually grew frustrated with some of Python's
+ limitations, fell in love with Guile, and well... now we have 8sync, which
+ is much more general anyway.
+
+@end itemize
+
+The motivation to build 8sync came out of
+ @uref{https://lists.gnu.org/archive/html/guile-devel/2015-10/msg00015.html,
+ a conversation}
+ at the FSF 30th party between Mark Weaver, David Thompson, Andrew
+ Engelbrecht, and Christopher Allan Webber over how to build
+ an asynchronous event loop for Guile and just what would be needed.
+
+A little over a month after that, hacking on 8sync began!
+
+
+@node 8sync's license and general comments on copyleft
+@chapter 8sync's license and general comments on copyleft
+
+8sync is released under the GNU LGPL (Lesser General Public License),
+ version 3 or later, as published by the Free Software Foundation.
+The short version of this is that if you distribute a modifications to
+ 8sync, whether alone or in some larger combination, must release the
+ corresponding source code.
+A program which uses this library, if distributed without source code,
+ must also allow relinking with a modified version of this library.
+In general, it is best to contribute them back to 8sync under the same terms;
+ we'd appreciate any enhancements or fixes to be contributed upstream to
+ 8sync itself.
+(This is an intentional oversimplification for brevity, please read the LGPL
+ for the precise terms.)
+
+This usage of the LGPL helps us ensure that 8sync and derivatives of
+8sync as a library will remain free.
+Though it is not a requirement, we request you use 8sync to build free
+ software rather than use it to contribute to the growing world of
+ proprietary software.
+
+The choice of the LGPL for 8sync was a strategic one, though in general,
+ we encourage stronger copyleft.
+(For more thinking on this position, see
+ @uref{https://www.gnu.org/licenses/why-not-lgpl.html,
+ Why you shouldn't use the Lesser GPL for your next library}.)
+
+In particular, if you are building a library or application that uses
+ 8sync in some useful way, consider releasing your program under the GNU
+ GPL or GNU AGPL!
+In a world where more and more software is locked down, where software is used
+ to restrict users, we could use every chance we can get to provide
+ protections so that software which is free remains free, and encourages even
+ more software freedom to be built upon it.
+
+So to answer the question, ``Can I build a proprietary program on top of
+ 8sync?'' our response is
+ ``Yes, but please don't.
+ Choose to release your software under a freedom-respecting license.
+ And help us turn the tide towards greater software freedom...
+ consider a strong copyleft license!''
@node Copying This Manual
projects / 8sync.git / blobdiff