Secluded Notes is a simple text editor that keeps each document as a part of its own executable. That part is called an "attachment", and the program encrypts/decrypts it on the fly with an AES 128-bit cipher. As long as you close the application, it automatically updates itself for the next run.
Slackpack is a package manager for Slackware Linux. It has a friendly GUI environment and can install packages, list installed packages, remove Slackware Linux packages (.tgz or .txz), and convert to .tgz format from .deb or .rpm. It can download Slackware Linux packages from package repositories, and can create .tgz packages from an application’s source code.