timeplotters is a collection of command line tools for visualizing temporal data. It is especially useful for visualizing data from ad-hoc program logs, helping you to spot patterns and anomalies that you would not otherwise see by just watching how the program works or by looking at the logs with the naked eye. Its input format is tailored to event types typically seen in program logs, and the visualization methods are tailored to the questions typically asked about program performance (e.g. distribution of activity durations).
PDFtk Server is a simple commandline tool for doing everyday things with PDF documents. You can use it to merge PDF documents or collate PDF page scans, split PDF pages into a new document, rotate PDF documents or pages, decrypt input as necessary (password required), encrypt output as desired, fill PDF forms with X/FDF data and/or flatten forms, generate FDF data stencils from PDF forms, apply a background watermark or a foreground stamp, report PDF metrics, bookmarks, and metadata, add/update PDF bookmarks or metadata, attach files to PDF pages or the PDF document, unpack PDF attachments, burst a PDF document into single pages, uncompress and re-compress page streams, and repair corrupted PDF files (where possible).