TheSky, from Software Bisque, Inc (a company that also develops telescope mounts) , is an astronomy program that plots the position of objects in the sky and includes a database of object names and other additional information.

ThinkTank is an outliner program or "Idea Processor" that arranges notes and ideas in a hierarchy that you can easily re-arrange. It was marketed as a tool for writing document outlines, brainstorming, notes, and todo lists. But it proved to be a very popular program, not just for writers, but for anyone who wanted to organize and move around ideas.

Thunderbird is an e-mail client based on the integrated Netscape/Mozilla e-mail client. With the release Firefox, it was spun off in to a separate standalone product. It includes the same HTML rendering engine used in Firefox to render HTML formatted messages.

TI-Writer was the standard word processor for the TI-99/4A. To use TI-Writer, you must have the TI-Writer cartridge (needed to load the disk software) and a TI-99/4A with the 32k RAM and disk expansion options.

TI-Artist, from INSCEBOT INC., is an easy to use general purpose drawing package for the TI-99/4A (not the original /4) that makes use of the high resolution bit-mapped graphics mode.

A once popular, powerful, easy to use project management program first released in 1984 from Breakthrough Software. Has unlimited number of tasks, dependencies, resources, and cost categories. It competed against Microsoft Project, and CA-SuperProject. Breakthrough Software merged with Symantec in 1987. The final version was 6.x for Windows.

Timeworks DOS Office, from Timeworks, Inc., is an office suite consisting of the Timeworks Word Writer PC word processor, the Timeworks SwftCalc spreadsheet, and the Timeworks Data Manager desktop database.

Toast was a popular CD mastering and burning application for classic Apple Macintosh. It was created by Astarte, who sold it to Adaptec, and later Roxio. Adaptec sold a different program for IBM PC compatibles named CD Creator

Backup Pro, from The Software Toolworks, is an easy to use backup program for MS-DOS. It features drop down menus and mouse support. It was sometimes bundled with OEM computers, and was sold for very low cost compared to others.

Toolworks Desk Reference is an electronic version of the New York Public Library Desk Reference. This reference contains a huge collection of various facts about ideas, advice, details and discoveries. It includes twenty-six subject areas and thousands of entries.

Toolworks DOS Tutor is an extensive DOS tutorial with detailed descriptions about the operation of common IBM PC compatibles, peripheral hardware, and the operation of DOS.

Top Priority is a Personal Information Management tool that keeps track of your appointments and tasks, set priorities, alerts you of periodic events, chart progress, and creates schedules. It offers an optional resident version that can run in the background while other DOS programs are in use. Can export data to Calendar Creator Plus.

Released by IBM in 1984, TopView was a text-mode windowed multitasker for the IBM PC, XT, and AT computer. It featured preemptive multitasking, text-based windowed task sessions, overlapping windows, and supports the use of a mouse. In part, it was one of the reasons why overlapping windows were added to Microsoft Windows 2.0. TopView was later overtaken by DesqView, OS/2, and Windows. For more information, see the Topview 1.00 Software Spotlight.

Touch Typist, from Newline software, is a small typing training program that is specific to Zenith-Z100 computers.

ToyBox II, later renamed to Magic Desk, is a simplified graphical menu system that lets you launch your DOS applications from a selection of tiled iconic buttons. Supports nested hierarchies, includes an icon editor, and a number of common icons.

Timeworks Translate-It is a program that automatically converts documents between different languages. It is all done locally on your computer, so you don't have to worry about Google stealing information from your documents.

Tree86, from The Aldridge Company, is an easy to use tree-based file manager for DOS.

Released in the early 90s by the Japanese company Trend Micro Devices, Inc (later just Trend Micro), Chip Away Viruses is a DOS based virus scanner that is intended to run from a hardware product built in to a PC motherboard before the system boots. It includes a custom embeddable DOS (called X-DOS), but it can be run from regular DOS. Trend Micro also produced the products PC Rx (A regular software virus scanner), and PC-cillin (a hardware/software combo that keeps critical boot information in a special device). Users sometimes misinterpreted the name "ChipAway Virus" as being a virus itself.

TTY Communications is a rudimentary dial up/terminal emulation telecommunications package sold with the Texas Instruments Personal Computer.

Borland's Turbo Lightning is a DOS based TSR spell checker. It can also look up Synonyms.

Turbo Tax, from ChipSoft, was a program that assists people in filing their tax returns.

TurboCAD is a low-cost 2D/3D Computer Aided Design program that competed with AutoCAD and Generic CADD. It was first available for DOS, and later Mac, Windows 3.x, and Windows 9x/NT.

Type Faces is a program that can print word processing documents using a number of fancy fonts. The fonts are rendered graphically so you are not dependent on the fonts included with your printer. At the smaller sizes, the fonts are letter quality. Type Faces supports formatting codes that you can insert in to your documents, such as right justify, centering, and underline.

Type Reader, from ExperVision, is an optical character recognition program that features the ability to correctly format complex documents, and the ability to export to a large number of different programs. TypeReader competed with OmniPage.

U.S. Atlas is a computerized world map with thousands of facts and statistics for US counties. Software Toolworks also produced a World Atlas, and a multimedia CD-ROM atlas.