DTRichTextEditorView a view that combines the richness of DTCoreText with UITextInput to give you the editing capabilities you need to change text editing on iOS forever.
The component is currently in an accelerated availability stage with one commercial pilot app being almost finished. Or put differently this is sort of a BETA stage where you can get access to the component for testing and adding the last few features to it that you need for your own special case of rich text editing.
UPDATE: Now available as time-limited Demo version.
DTRichTextEditorView is fantastic! I was able to implement syntax highlighting behavior in under an hour. Performance is stellar as well. - Illya Busigin
This component contains the functionality of the genstrings command line utility but in a static library that you can add to developer tools. It is used by our app Linguan for scanning source files for instances of the NSLocalizedString macros.
DTDownload started out as a wrapper around NSURLConnection when I needed resumable file downloads for iCatalog. It has since grown into several parts. For file and image caching you can use DTDownloadCache, for queueing up a large number of downloads use DTDownloadQueue.
This component allows you to get all the information fields from a X.509 certificate. You get DTCertificate to get the raw information as well as DTCertificateViewer which is a view controller modeled after the certificate viewer built into iOS. More details
Safari uses the WebKit class WebArchive to transfer rich data from e.g. Safari. This project aims to give you the capability of accepting such pasteboard data in your apps. WebArchive and the related WebRessource classes are tightly coubled with WebKit and private. This project is a reverse-engineered class giving you the same functionality on iOS.
For example you could allow your users to copy something from a web page and paste it into your app preserving the formatting.