This is a list of libraries for Palm developers.

Commercial Products:
    Package: Object Library for Palm OS
    Vendor: TeT
    Provides: Object-oriented library for Palm OS deveopment
    Tool Compatibility: CodeWarrior 6 and up
    Library type: C++ class library
    Price: $43
    Licensing: Commercial
    Commentary: This appears to be an MFC-like class library for Palm OS development. I don't know how deep the similarities go, but it has a CPalmApp base class and a C preprocessor-based message map definition mechanism.

    Package: PalmAccess
    Vendor: EHand
    Provides: Conduit development for any COM-enabled language
    Tool Compatibility: The site mentions VB, Delphi and Java, but it's probably not limited to those three.
    Library type: COM object
    Price: $390 for up to 500 users; negotiated licensing thereafter
    Licensing: Commercial

    Package: Palm SDK Foundation Classes
    Author: Mike MacMartin
    Provides: Object-oriented library for Palm OS deveopment
    Tool Compatibility: PRC-Tools
    Library type: C++ class library
    Price: Free
    Licensing: GPL

    Package: TurboSync
    Vendor: Tabdee
    Provides: Conduit development kit for Delphi
    Tool Compatibility: Borland Delphi 4 and 5
    Library type: VCL components
    Price: $60
    Licensing: Commercial

Shareware and Freeware Products:
    Package: Delphi Conduit Class Library
    Author: Paul Gilbert
    Provides: Conduit development kit for Delphi
    Tool Compatibility: Borland Delphi 5, possibly Delphi 4 with tweaking
    Library type: VCL components
    Price: Free
    Licensing: Postcardware

    Package: iKnapsack
    Author: Adam Tow
    Provides: A tight Internet/Palm integration mechanism.
    Tool Compatibility: CodeWarrior
    Library type: Shared library
    Licensing: BSD-style freeware
    Commentary: iKnapsack provides a way to convert Internet content to Palm databases. The simplest example is grabbing addresses off a web page and adding them to your Address Book, but this package's open design lets you write plugins that translate any web content to any Palm database.

    Package: MathLib
    Author: Rick Heubner, GNU Project
    Provides: A Standard C math library
    Tool Compatibility: CodeWarrior, GCC
    Library type: Shared library
    Licensing: LGPL
    Commentary: If you're a C programmer and you need to do floating point arithmetic or trig, you need MathLib. This library is a Palm OS port of the math portion of the GNU Standard C Library (glibc). Since Palm OS itself has very weak floating point math support, this library fills in some pretty big gaps.

    Package: Palm Application Framework
    Vendor: Bear River
    Provides: C++ wrapper for Palm OS programming
    Tool Compatibility: CodeWarrior
    Library type: Static link library
    Licensing: Open Source
    Commentary: This is a C++ framework for developing Palm OS applications. It currently only works with CodeWarrior, though since it has source available you could theoretically port it to the GNU toolchain.

    Package: Zen Plus
    Vendor: Class Action
    Provides: C++ wrapper for Palm OS programming
    Tool Compatibility: CodeWarrior, and allegedly GCC
    Library type: Static link library
    Licensing: Open Source
    Commentary: Zen Plus (previously called "Teenee") is similar to PAF in that it's a C++ application framework for Palm OS programming. Its differences are that it's more lightweight, and that it is said to work with GCC. A quick tour of the sources makes it plain that the developers haven't gone out of their way to make this easy, however.