Eventually this may be a markdown to PDF, ePUB, MOBI processor. For now it's just something I'm playing around with, so use at your own risk

Uses weasyprint to create PDFs using HTML

Slaw is a lightweight library for rendering and generating Akoma Ntoso acts from plain text and PDF documents.

Sinatra extension to add support for pdf rendering with Prawn templates.

A Prawn PDF component which adds basic HTML support

Optical mark recognition of multiple-choice tests and surveys. Low-level ruby library to generate response sheets in PDF form and to automatically score manually filled-out forms.

Report Abstract Interface. Creates text, html, pdf and rtf output, based on a common framework.

mn2pdf converts Metanorma XML into PDF. This gem is a wrapper around mn2pdf.jar available from https://github.com/metanorma/mn2pdf, with versions matching the JAR file.

Ruby library for creating Swiss QR-Bills as PDF with Prawn

Inline PDF templates that use prawn.

A HTML5 client-side solution for generating PDFs.

Creates polish invoices and proforms as HTML or PDF files

PDF rending plugin for Rails using FlyingSaucer.

Convert office document to pdf and swf

PDF rending plugin for Rails using FlyingSaucer.

Export list of html or xhtml files to pdfs with 'wkhtmltopdf'

Client library for the DocSpring PDF generation and e-signature service

DSL for creating clean CSV, XLSX, and PDF reports in Ruby. Extracted from Brighter Planet's corporate reporting system.

simple wrapper around CLI for extracting text from PDF and Word documents

Hundreds of styles fueling Authorea.com's exporter to PDF. Use with the "exportstylist" gem for a Ruby API.