XESS is a spreadsheet for UNIX, Linux, OpenVMS, and Windows NT which supports user-configurable 3-D workbooks with up to 10 million rows, enhanced display and print formatting, international locales (including multi-byte languages), full Y2K compliance, Web enablement, and a high level of compatibility with the Excel and Lotus spreadsheet products. It includes filters for Excel 97, Excel 2000, and Lotus spreadsheets.
XFMail is an X11 application for receiving electronic mail. It implements most of its email functionality internally so that it does not depend on a lot of extra packages. It supports POP3, MBOX, IMAP4, sendmail, and SMTP. It has built-in support for interfacing with PGP, GPG, ispell/aspell, faces, LDAP, and esound. It runs on most Unix variants.
xine is a free multimedia player. It plays back CDs, DVDs, and VCDs. It also decodes multimedia files like AVI, MOV, WMV, and MP3 from local disk drives, and displays multimedia streamed over the Internet. It interprets many of the most common multimedia formats available--and some of the most uncommon formats, too. All those features come in a reusable library (xine-lib) which can easily be embedded in your applications.