Web Distributed Authoring & Versioning Daniel Wittmer Mike Fisk

Outline Project vision Environment Expected Risks Post Mortem Demo

Project Vision Users access web servers as file servers Through a mounted file system Through clients with special support Read-only access through normal browser Server keeps version history of changes Users can collaboratively edit documents and publish web pages

Technology HTTP extensions for distributed authoring IETF RFC 2518 Already implemented for Apache Additional extensions for versioning IETF draft standard No finished implementations (client or server) Our project: a versioning server

Project Environment Standards body (IETF) Distributed authoring (DA) standardized Versioning in progress (DeltaV WG) Apache, WebDAV module Infrastructure that we don’t control Supports DA, but not versioning Open Source Community C code, security & usability expectations

Standards Risks We perceived risk that standard could change even though it seemed stable A new version was released during the project Better documentation Negligible technical changes Some provisions designed to simplify implementation clashed with our design Poorly designed authorization assumptions No mapping of original auths to version repository

Design Change: CVS We planned on using CVS as versioning infrastructure Despite many identified risks WebDAV standard specifies that metadata represented in XML CVS interface didn’t match these requirements well Value only as a compact storage optimization Result: Dropped CVS from architecture

Feature Set Evolution Risks of time to market and developer resources Shed features along the way in order to meet our deadline (Microsoft model) Focused on features usable by existing (non-versioning) clients Developed a strategy for future features

Apache WebDA(V) Both a boon and a bane Apache is a popular 142kloc system Basic WebDAV without versioning is a 94 page standard --- already implemented in 18kloc Legacy code Problems using architecture for new tasks 96 pages of new standard

Greg Stein – Third Wheel Development Manager, in the Commerce Server and Site Server groups, Microsoft Co-founder and the Corporate Technologist of eShop, one of the first electronic commerce software companies, before its acquisition by Microsoft in Now “non-employed” open source developer Wrote Apache WebDAV codebase We don’t like his code

Poor Legacy Modularization Existing WebDAV module has a poorly executed modularization A monolithic codebase split into pieces Interfaces very brittle, complex, incomplete Unexpected time sink (Risk of bad scheduling estimates) Our implementation more kludgey than desired Fixing existing code is out of project scope

Summary Update On time Overcame implementation challenges On budget Have been stalling on getting boffice space Streamlined Feature Set Imperceptible loss to current users

Futures Future Development Efforts Add Basic-Server-Workspace Option Add Basic-Client-Workspace Option Optimized Storage Funding Requirements Gross revenue: $0 (it’s open source) Need staff of 3 FTE for next FY If you funnel support through the Free Software Foundation, your support is tax deductible as a charity donation

DEMONSTRATION Mac WebDA(V) client Versioning Apache server Manually enable versioning