Does anyone know of a framework or library to support PERT charts in JavaScript?

[Peter Newman]

This is for a personal project, so I'm looking for something that's free. There are some commercial products out there, but they're (way) beyond my budget at the moment. 

Google's Charts API does not appear to include the PERT chart; however, is there a way to create one from existing resources? Does someone have an example? I'm just learning  JavaScript and HTML.

The project I have in mind is to provide a visual representation of a mainframe-hosted batch process or schedule, which contains start and end jobs with one or more jobs in between them. The PERT chart with durations and dependencies would seem to be a good fit for the requirements. The input to the process would be an XML file created from an extract from the mainframe containing elements for job information and metrics in addition to the predecessors of and successors to the jobs. 

I've been testing the use of the HTML5 canvas to  dynamically create the shapes and connections to represent the batch schedule, but this may be complicated for a large number of jobs, which could compromise the size of the canvas. However, I'm willing to go in that direction in the absence of a (more professional) looking framework or library.

I would appreciate any guidance, thank you.