To use Exceptions for C, a programmer compiles and links XCEPT.C into the program and #includes XCEPT.H in source files that use Exceptions for C. Three keywords are used to delineate use of exceptions: xc_with_handling, xc_on_exception, and xc_end_exception. Code for normal cases is placed after xc_with_handling, and exception handling code is placed after xc_on_exception. Handlers that don't recognize a particular exception can invoke xc_reraise(), to pass the exception ot the next handler in the calls stack. xc_cleanup and xc_end_cleanup, can be used to mark code that executes normally and whether there has been an exception or not.

The package includes the library (provided as ANSI C source code) and documentation in the header file. Exceptions for C is available in MS-DOS and Macintosh formatted disks, at $30 for a single copy. A site license is available for $30 for the first user plus $6 for each additional user, minimum 5 users. Contact Koyn Software, 1754 Sprucedale, St. Louis, MO 63146, (314) 878-9725.

X/DOS is distributed as a DOS-linkable library. A UNIX C client can be recompiled and linked with X/DOS to create a standard DOS application than runs on a standalone PC. No special operating environment or X server is required. X/DOS provides a cross-development tool to create graphic applications that are portable between DOS and UNIX. X/DOS supports all X drawing capabilities and X events. Several fonts are supplied with X/DOS, and standard X fonts may be used.

Prices for X/DOS begin at $295. Educational version of X/DOS are available for $99. Contact Software Migration, 9 Commodore Dr., Suite 404, Emeryville, CA 94608, (510) 658-5436.

The HALO Imaging Library is divided into several functional groups: Image Management Functions to create and manage images in memory; Image Conversion Functions to convert images from one class to another; Image Enhancement Functions to adjust and refine brightness, contrast, and gamma characteristics, and to enhance an image with special effects such as blur, pixelize, sculpt, emboss, and overlay; Image Transformation Functions to rotate, transpose, flip, or spatially distort and image; Image File Format Functions to read and write image files including TIFF, JPG, GIF, TGA, PCX, BMP, CUT, EPS (write only), and PICT.

HALO Imaging Library is available for MS-Windows, OS/2, Macintosh, UNIX/Motif, and UNIX/OPEN LOOK. The library contains an application program and source code samples that demonstrate the functions, along with platform-specific image display and print routines.

A single workstation license for HALO Imaging Library for Windows is $595. Other platform versions are planned for release. Contact Media Cybernetics, 8484 Georgia Ave., Silver Spring, MD 20910, (301) 495-3305; FAX: (301) 495-5964.

Alydaar technology is based on Algebraic and functional programming systems and is modeled after the symbolic manipulators designed to facilitate mathematic manipulations. Alydaar lets the users construct descriptions of each portion of the source language. This model accommodates information such as left/right associativity of operators and also operator precedence, adicness (monadic, dyadic, and triadic), operands, data conversion issues, type conversion issues, structural and elementary levels, and language addressing differences present in the implied abstract machine. The translator augmentation process uses a high-level, rule-based language.

Alydaar supports: macro preprocessing, white space management, and comment processing; identification of expressional issues, description of statement level topics, and execution-time statements; resolution of declaration issues; and teaching the translator context syntax and semantics.

Other features of Alydaar include: detailed specification of optimization and code-generation issues; saving interactive context for later use or compiling it into a C or Ada application; and target source code. Alydaar translation costs range from 25 to 50 cents per line translated. Contact Alydaar Software Corporation, 216 Crown St., Suite 502A, New Haven, CT 06510, (203) 787-2544; FAX (203) 787-1440.

To implement a DSP design, Block Diagram proves the algorithm, debugs it, and sets up "what-if" situations in a visual environment. The code generator then produces C code for the algorithm, which may be compiled with the DSP chip manufacturer's C compiler. This enables the program to run real-time on a DSP. Previously, such capability was typically found on workstations.

Hypersignal-Windows Block Code Generator is available for $2995. Contact Hyperception, Inc., 9550 Skillman, LB 125, Dallas, TX 75243, (214) 343-8525; FAX: (214) 343-2457.

Besides creating methods for building and traversing relationships, DataDraw also creates binary-file load and save functions. DataDraw includes code-generation source code, so users can customize DataDraw's output. DataDraw sells for $179 and comes with a 30-day, money-back guarantee. Contact DataDraw, 1613 Butano Dr., Milpitas, CA 95035, BBS: (408) 956-0576.

DMalloc features include: automatically checking the heap when an allocation function is called; surrounding the allocated memory unit with "safeguards", so memory overwrites are detected but don't destroy the heap; cooperating with debuggers like CodeView and SoftICE in setting breakpoints; and identifying allocated memory units by source file and line of allocation. (Source modules must be recompiled to use this feature.) DMalloc can be popped up with the [PrtScreen] key to view status and examine or edit memory. DMalloc can be configured to reflect the working environment, during debugging, or by inserting calls to the DMalloc API into the program.

DMalloc works with Microsoft C/C++ v5.1 or higher. The large memory model is required. DMalloc is marketed as shareware, and is available on CompuServe, through ASP-approved BBSes, and ASP-approved shareware vendors. The registered version of DMalloc is $47 and an unregistered evaluation disk is $5. Contact Software & Consulting, Hietzinger Hauptstrasse 40c, A-1130 Vienna, Austria, FAX: (+43) 1 876 46 094; CompuServe: [100015,551].

Purify 2 supports Sun's SPARC platforms. Purify 2 is $4,000 per floating network license. Contact Pure Software Inc., 1309 South Mary Ave., Sunnyvale, CA 94087, (408) 720-1600; FAX: (408)720-9200; email: info@pure.com.

The categories of software in ISCL include: tutorials, compilers, communications, matrix/numerical, graphical user interfaces, memory management, database/ISAM, neural networks, and source utilities. Some example volumes are: GNU 386 C++ compiler, Hypertext tutorial for C++, GOOD C++ comm lib, C++ math matrix class with overloaded operators, GUI TesSe-Ract Development Tools Shareware, SNAV (the Screen Navigator) 1.21 library of reusable objects, Btrieve class for C++, Paradox C engine C++ class definitions, ANSI C and C++ declaration composer and decoder, and Prototype generator for C++.

All ISCL volumes are available as individual volumes or as a complete set, and may be freely copied and distributed. All material is in the public domain, or is available as shareware. Volumes are available on 3 1/2 inch and 5 1/4 inch disks, as well as other media, including magnetic media, from forums such as BBSs. Contact ImageSoft Inc., 2 Haven Ave., Port Washington, NY 11050, (516) 767-2233; FAX: (516) 767-9067.