.Net library consisting of three classes for simplified asynchronous I/O (AsyncStream), using alternate data streams (AlternateStreams), and efficient stream peeking and seeking (BetterBufferedStream). BetterStreams can easily improve the performance of new or existing applications, sometimes dramatically, with as little as a single-line change to the code. AsyncStream wraps an existing stream and provides asynchronous I/O via the standard Read(), ReadByte(), Write(), and WriteByte() methods; if called on the wrapped stream directly these would require waiting for I/O to the underlying device (such as a disk) but the AsyncStream asynchronously and automatically fills or flushes its internal buffer from or to the wrapped stream using a background thread and will never block so long as sufficient bytes are available in the buffer. Even if your application logic is already built around synchronous I/O, making it asynchronous typically requires nothing more than wrapping the original stream in an AsyncStream. AsyncStreams also provide elegant exception handling, properties for fine-tuning performance and behavior when desired, and, like BetterBufferedStreams, efficient seeking. AlternateStreams enables you to read, write, delete, create and list alternate data streams (ADS) in an NTFS file. Under NTFS, each file has a "main" unnamed stream (this is the one the Framework's file I/O classes manipulate) as well as zero or more "alternate" named streams; for example, Internet Explorer uses an alternate stream named "Zone.Identifier" to record which security zone a downloaded file came from. Aside from conveniently storing metadata, they can also be used to create "compound storage" for application data; instead of, for example, sequentially serializing ten objects to the "main" fie stream (requiring the entire file to be rewritten if any but the last object changes) each object can be serialized to its own, individually modifiable alternate stream.