Hi, There are three known WSGI implementations of the Zope 2 publisher. I've had a look at them and made some notes about what I think provides the best story: ## Zope 2.13 WSGIPublisher Pros: * Allows distributed transaction management with repoze.tm2 * Allows distributed retry with repoze.retry * Ships with Zope * Quite simple Cons: * Requires repoze.tm2 and repoze.rety * Does not properly emit publication events - possible patch in https://gist.github.com/1548061 * Does not do error handling or exception views * Claims not to properly implement streaming (though there is some code for it) * Probably less well tested than infrae.wsgi and repoze.zope2 (at least there is zero documentation) ## infrae.wsgi Pros: * Clean and well documented * Properly emits publication events * Supports streaming * Supports simplified virtual hosting with X-VHM-Host * Supports exception handling / error views * Reportedly has significant production use Cons: * Not 100% compatible (but close and fixable) - fix to make plone.transformchain work is here: https://gist.github.com/1547328 * Unnecessary five.grok dependency (but easy to rewrite to use ZCML registration) * No support for middleware transaction and retry management, so these can't be distributed across a WSGI pipeline * Error logging will not support ZMI error_log and assumes single process * Error handling is slightly different to standard publisher's exception views, and also does not honour existing standard_error_message etc ## repoze.zope2 Pros: * Clean and well documented * Reimplements and simplifies the BaseRequest.traverse() code, with comments * Supports distributed transaction management and retry Cons: * Replicates a lot of Zope startup code * Has now-unnecessary code to manage instances and configuration * repoze.obob abstraction is unnecessary since nothing else uses this * Does not emit publication events - possible patch in http://bugs.repoze.org/issue181 * Does not do error handling or exception views * Problems with file resources (does not properly traverse to browserDefault() result) -- possible patch in http://bugs.repoze.org/issue64 * Requires various middleware (repoze.tm, repoze.retry, repoze.vhm) ## Suggested approach going forward * Integrate infrae.wsgi into Zope 2 * Remove its five.grok dependency * Use the same exception-views protocol as ZPublisher (mainly, that the view name is ``index.html``) * Stop using __ 'private' variables in response.py to make it easier to work with * Add some BBB support for existing error logging and error messages Thoughts? Martin