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Download and Install E 0.8.9.1

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Highlights this Version
Variants and Subsets of E
Dependencies

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Download by Platforms & Versions

Earlier versions of E have been tested and run on Windows 95, Windows 98, and Linux. It should run without difficulty on Windows NT and on other UNIX platforms. If you experience any problems, please let me know.

The Installing links below describe how to install, and run various forms of the binary distribution. The Building links describe how to build E from the source release. The Download links will download each corresponding form of the release to your machine.

The contents of the Unix/Linux source distributions are identical to that of the Win* source distributions, except for the use of gzipped tar files rather than zip files, and the use of respective platform's newline conventions for the text files. Since gzipped tar files are somewhat smaller, Win* users should download these instead if they can decompress them and if their tools are tolerant of the Unix newline convention. The commercial WinZip program seems to do a good job on both compression types. Also, Info-Zip's unzip can be used to unpack the zip files on any platform.

The binary distributions, on the other hand, are specific to each platform. We do not currently cross-compile. The Linux binary distribution is built from the common source distribution on Linux, and similarly for Windows. The link above is a Linux binary distribution for the 386 architecture and a glibc-supporting version of Linux (this includes RedHat 6.1, which is what we're using). If you need E for a different Unix/Linux configuration, you should build E from the source distribution.

Highlights of this Version

E 0.8.9.1 is a branch off of 0.8.9, in which many of the bugs fixed in the internal development successors of 0.8.9 have been applied to 0.8.9 itself. This allows production work in E to benefit from these bug fixes while we all await the release of 0.8.10.

The main fixes are

• Bill's fixes to VatTP (aka net/data) to enable it to run without the cryptix jars & properties files, and therefore to be able to run on Java 1.3. 0.8.9 itself could only run on JDK >= 1.1.7 & JDK < 1.3. This release should run on all JDKs >= 1.2. This will be the last production release to support any JDKs < 1.3; 0.8.10 will only support JDKs >= 1.3.

• Bill's further fixes to the random number generator so that it remains unguessable even when the native microsecond timer code is absent (which, currently, is always).

• The fixes to Runner to repair a deadlock bug diagnosed by Dean, and to fix a bug that would have impaired multiple vats per JVM, noticed by Chris Hibbert. Further fixes to remove the notion of a "global" default Runner, with much help from Dean.

• The previous installer would crash on a null pointer if there wasn't a java.exe on the PATH. This is now fixed. If this installer still crashes on you, please let me know.

• Several improvements to the Makefiles and the C code for the installer that should make them more portable.

• The 0.8.9.1 grammar accepts the "var" keyword, but treats it as a synonym for define. Since "var" was one of the few non-downward compatible changes to the E grammar that happened since 0.8.9, this change should allow most normal 0.8.10 compatible code to run on 0.8.9.1.

Variants and Subsets of E

A complete E system is persistent, distributed, and capability-secure both within and between processes. Incomplete variants of E are tagged by which of these features are left out.

A non-persistent E is called time-local since an object only exist as long as its hosting process does. This release is time-local and so is prefixed with "tl-". We expect to be adding the persistence code back in as part of the 0.9.x release.

A non-distributed E is called space-local if an object and all references to it only exist within its hosting process. This release is distributed and so is not prefixed with "sl-". To make a space-local variant of this release, you need merely remove the org.erights.e.net package tree.

E by definition provides distributed capability-security -- the ability for objects in mutually suspicious processes to safely cooperate. If it looks like E and it quacks like E, it might be a duck; but if it doesn't provide distributed capability security, it's not E. A system that's otherwise equivalent to E, but doesn't provide distributed capability security, is called daffE. A distributed E can only be implemented by means of strong crypto, of course, for which we are bundling a subset of the Cryptix library. In a space-local system, no distributed insecurity can arise, so such a system would be an sl-E rather than an sl-daffE. This release provides distributed security and so is an E rather than a daffE.

E is designed to provide local capabillity-security -- the ability for mutually suspicious objects hosted by the same process to safely cooperate, and the use of capability discipline to determine which of its hosting process's authorities it may exercise. Such objects could be executing untrusted code -- code that the hosting process (or its owner) doesn't need to fully trust. Currently, however, E's E-to-Java binding exposes all of public static Java to all E code, and the Java libraries do not follow capability discipline. Therefore this release hosts only-trusted-code and so is prefixed with "otc-". (Note that all conventional cryptographic code, such as PGP, is also assumed to be fully locally trusted, and provides only distributed security.) We expect to provide local capability security, including confinement, as part of the 1.0.x release.

E is designed to support automatic mobile code (as in PassByCopy objects). However, were this to be provided in a release that was not locally secure, this would invalidate our distributed security and worse. Therefore mobile code support must wait until E supports full local capability security including confinement.

Dependencies

Versions & Types of Java

In referring to various versions of Java, we follow Sun's terminology and numbering. A Java Runtime, or jre, is adequate to run standard Java binary programs (class files & resources). A Java Development Kit, or jdk, is adequate both to build a program from sources and to run it. A jdk is a superset of the corresponding jre, and their version numbers are always in synch. Each successive version of the jdk/jre from Sun effectively defines a new version of the Java & JVM standards, except that Sun has introduced a numbering inconsistency: The Java/JVM 2.x standard corresponds to Sun's jdk/jre 1.2.x. We ignore this inconsistency and refer to both as 2.x.

E requires a jre >= 1.2. To build E from sources, a corresponding jdk is required.

E makes heavier use of Java reflection than most Java vendors have encountered. Some implementations of Java (like IBM's VisualAge 1.1.7) have failed to run E because of bugs in their implementation of reflection. As you encounter information to add to the table below, please let me know.

Some places to get some a jre or jdk:

Build-Only Dependencies

If you are only installing E from a binary distribution, or only rebuilding the Java portion for your own use, you can ignore this section. However, if you wish to build an E distribution from sources, then you will need the equivalent of the following tools as well.

The Cygwin Distribution

The E building process relies on a number of UNIX tools. These are available for Windows from Cygnus Support as the Cygwin package. If you wish to build E on Windows, you should download and install at least Beta version 20.

BYacc/J (Berkeley Yacc for Java)

The E source distribution contains the executable binary program byaccj.exe for Windows, and byaccj for Linux/386/glibc. These are actually BYacc/Java from Bob Jamison and others. BYacc/Java is the Berkeley Yacc program extended with a "-j" flag and others for producing Java output. BYacc/Java is covered by the Berkeley License. If you are on a Unix system other than glibc Linux, you need to download your own version of byaccj and overwrite the one in src/bin/linux-386-glibc that our Makefile is using.

Zip Files

Our build process packs up the *.zip files in the distribution by using Info-Zip's highy portable, and highly ported, zip program. Info-Zip's zipping tools are open-sourced with a license that seems to resemble the X11 license, but before redistributing it, you should read it for yourself. The E distributions do not bundle in these tools.