Zope is an open source web application server that pioneered object publishing, traversal, and a persistent object storage database called ZODB. It had early success in the late 1990s and 2000s but also faced challenges including a complex architecture, backwards compatibility issues, and lack of hype. Today the Zope community lives on through related projects like Plone, Buildout, Repoze, Pyramid, and Deliverance which continue to develop and improve upon Zope's innovations.

1. Zope is Dead,
Long Live Zope!
Lennart Regebro
Krakow, June 2011

2. “Zope Is Python's Killer App”
Jon Udell – BYTE, February 2000

3. Pop Quiz!

4. Google trends: “Zope”

5. A brief history of Zope

6. Year: 1996
● Duke Nukem 3D
● Altavista
● Web development is CGI and Perl
● Maybe php, if you are lucky
● Spice Girls
● Presentations had bullet lists

7. Location: An airplane
● Jim Fulton creates Bobo
● Object publishing
● Traversal
● Open Source

8. Year: 1997 (maybe)
● BoboPOS: A persistent object storage
● DTML: Innovative HTML templating
● Principia: A web framework
● Uses Bobo and BoboPOS and DTML

9. Year: 1998
Principia becomes open source
and is renamed Zope

10. Year: 2001
The warts of Zope starts being a problem
A rewrite is started

11. Year: 2004
The rewrite is released as Zope 3

12. Year: 2009
Zope 3 is renamed BlueBream

13. Year: 2011

14. Zope?

15. Zope!

16. Object Publishing
● You use the URL it to find an object
● The object is then asked to render itself
● No stdout is used
● No loading of the whole program every
request
● Your application is not a collection of
separate scripts on the disk

17. Traversal
● Example path: /calendar/2011/06/17/google
● / returns a root object
● You ask the root object for the 'calendar'
subobject
● You ask calendar for the '2011' object
● Etc until you reach the 'google' object
● Which you ask to render itself
● No more /calendar.php?item=84735

18. Many other nice things
● Fine grained access control
● User management
● Internationalization
● Reusable extension products
● Zope Page Templates
● Through-the-web Development

19. Digression: Database Fashions
● 1990's: Object-Oriented Databases
● Early 2000's: In-memory databases
● Mid 2000's: Transparent persistence
● Now: Schemaless / NoSQL databases and
sharding

20. ZODB
● ZODB is an object-oriented,
● In-memory transactional,
● Transparently persistent,
● Schemaless database.
● It's hierarchical and logging as well.

21. The facepalms of Zope

22. Through-the-web Development
● Code in the database
● No version control
● Restricted Python for security reasons
● You can't use normal development tools

23. Development dead-ends
● The TTW development was not OOP
● You end up with a pile of scripts
● Solution: ZClasses
● Actually was even worse
● Required re-write
● Disk-based products
● The right solution
● But: Required rewrite. Again.

24. The Zope Ghetto
● Zope had to invent everything
● Later others reinvented it
● Zope ended up with its own solution

25. Monolithic

26. Magic attributes and methods
● __bobo_traverse__()
● Special traverse logic
● __before_publishing_traverse__()
● Also special traverse logic
● __call__()
● Is what renders the object.
● Unless is has an index_html attribute
– Unless there is a default view component
● Unless there is a __browser_default__()

27. Acquisition
● Like inheritance but completely different
● All objects “acquire” the attributes of objects
above them in the object hierarchy
● The complete opposite of namespaces

28. Backwards compatibility forever

29. Bad karma
● Bad documentation
● No ability to hype
● Ugly web page

30. Bad learning curve
Just gets worse
Starts easy

31. Zope 3!

32. Fixed all the problems
● Not TTW
● An awesome aspect-inspirect component
architecture!
● Everything pluggable
● Acquisition only when you ask for it
● Super-mega-enterprisey!

33. Nicer learning curve

34. But...
● Not backwards compatible
● Death by abstraction:
● Everything is an adapter or a utility
● All files called the same:
● configure.zcml, interfaces.py, browser.py, adapters.py,
configure.zcml again.
● “A conspiracy on the hard-disk”
– Jörgen Modin
● Still installed as a monolith
● Confusing name

35. Five
Zope 3's awesome component architecture
But in Zope 2

36. Mmmmmyeah...

37. The King is Dead?

38. State of Zope 2011

39. Plone
● Fantastic Content Management System
● Loads of users
● Great community
● Best conferences

41. Buildout!
● Deployment tool
● For development and production
● Extensible with recipes
● Even used by prominent Django-people!

42. Repoze
● A re-imagining of the Zope publisher
● A WSGI pipeline of middleware
● Transactions
● Security
● Indexing
● Quickly picked up by Pylons/TG crowd

44. Cooperation!
Pylons ♥ BFG = True

45. Pyramid
● Routing or Traversal
● Persistance agnostic (can even use ZODB)
● Fast and extensible
● Best T-shirt of Pycon 2011

47. Deliverance / Diazo
● A whole new way to theme sites
● Rules to map items from content to theme
● Skin sites in hours
● Make several apps look the same

50. Hot or Not?
✗ ✓

51. Cool Zope Things
● Object publishing
● ZODB
● Zope Component Architecture
● Buildout
● Repoze
● Pyramid
● Deliverance / Diazo

53. Questions?
regebro@gmail.com