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Download and Install E 0.8.10alpha1

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Earlier versions of E have been tested and run on MSWindows (95, 98 FE, NT, 2K), and Linux. It should run on other UNIX platforms as well, given an adequate version of Java and bash (see below). It should also run without problems on MSWindows 98 SE and on ME, but as far as we are aware, no one has tried this. If you experience any problems, or have any other informative experiences, please let me know, or report a bug.

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.

Highlights of this Version

As each of these issues are discussed in email or in the bug tracking system, we will link the paragraphs below to the relevant roots.

E 0.8.10alpha1 is the first version of E to simultaneously be

• Distributed (hence no "sl-" prefix, as explained below). This version implements the 2vat subset of the much improved CapTP protocol that's been on the drawing board for so long. Chief among the CapTP improvements: We now have full promise pipelining. Since we've postponed making the 3vat introduction cases work, we have instead made them fail clean, and verified that they do so.
  ( Track this issue... )

  This version also incorporates Bill Frantz's improvements to VatTP, merged from the branch release 0.8.9.1b. Between the new VatTP and the new CapTP, we are more confident than ever in our distributed security. (And so this is an "E" rather than a "daffE", as explained below.)
  ( Track this issue... )

• Persistent (hence no "tl-" prefix). The version has an early, experimental preliminary form of support for identity persistence. With identity persistence, the application still has to do all the "manual" work to save an restore object state, but the app can now securely reassociate old persistent identities (as designated by exported SturdyRefs and <cap:...> URI strings) with the manually revived objects. To aid in this manual work, E programs can use the new Serializer and Unserializer, which default to rules suitable for checkpointing and reviving persistent object state. Not yet ready for prime time.
  ( Track this issue... )

• Confining (hence no "otc-" prefix). As with 0.8.9t and 0.8.9t.1a, *.emakers are imported with no real authority to affect the world outside themselves. All authority must be granted, and so can be granted according to POLA. Nothing new here, but we've never had this in a distributed version of E before.
  ( see Mark Seaborn's thoughts on a module system for E )

  This issue appears again at a higher layer: Marc Stiegler is preparing an all out assault on the caplet environment -- gui support for interactive POLA authorization of untrusted applications (themselves represented as emakers).
  ( Track this issue... )

Many tool improvements:

• The evalServer enables remote evaluation of expressions, and the reporting back of the results. This is suitable for remote Elmer-like command line interaction (though Elmer hasn't yet been changed to use it), simulated command line interaction (as in the new Updoc), or those needing to bootstrap up multi-vat computation (ie, it should replace eBrowser's current use of the vatMaker).
  ( Track this issue... )

• Updoc has been extended to do multi-vat testing, and to properly obey blockAtTop(), continueAtTop(), and exitAtTop() messages sent by the scripts being tested. In combination, this has enabled us to write replayable regression tests of CapTP functionality. Unfortunately, in the process, we've temporarily lost the ability to iterate of a directory tree.
  ( Track this issue... )

• eBrowser is rapidly becoming a serious development tool.
  • It now does intelligent indentation based on the lexical structure of the language. (Actually, it currently parses as well as lexes, but it should only need to lex.) (Note: Elmer now uses this indenter also, but neither properly unindents closing brackets.)
  • The first syntax error causes the offending code to be selected in the editor, leading to a more Smalltalk-like rapid correction loops.
  • It spins off a separate vat to calculate the left and right outline panes in the background whenever the source has changed. Even though the panes are, at any moment, often slightly stale, the effect works amazingly well.
  • Just coming in under the wire, eBrowser now supports drag-n-drop. Both among eBrowsers, and also between eBrowser and the rest of the desktop.

  ( Track this issue... )

• Bug Tracking. As you can see from all these "Track this issue..." annotations, due to Steve Jenson (Thanks!), starting with this release, we are making extensive use of the bug tracking system. He had us try several before we selected the SourceForge bug tracking software. We selected this one because it made life easiest for someone who had just encountered a bug and wanted to report it, without having encountered the bug tracking system before: new bugs can be entered without reading any documentation or starting an account. So, everyone, please make use of this convenience and report problems as you find them.

Language improvements:

• The new, much improved, Seaborn-Karp when-catch-finally expression:
  • In "when (x) -> done(y) {...", the success case will only see a y that's the same as x. Further, a remote promise only resolved once per vat, and so we can't get an intra-vat divergent resolution inconsistency. (We all agree that we can't prevent a malicious vat from causing an inter-vat inconsistency.) (*** need to find email link)
  • The syntax and semantics are now more parallel to try-catch-finally: there can be a chain of catch clauses followed by an optional finally clause. These catch not just a broken resolution, but any problems thrown by the success clause. (*** need to find email link)
  • The when-catch-finally expression evaluates to a promise for the value its done function will return. (The done function is the result of expanding everything to the left of the "->".) (*** need to find email link)

   

• Swinging Vats. We figured out and solved (due to Dean, thanks!) a terrible lurking concurrency conflict between E's vat-scheduling assumptions vs AWT/Swing. We now have front-end ("fe") vats, that execute in the AWT-Event thread and use the AWT Event queue for their turns, and back-end ("be") vats, that have their own thread and queue. All synchronous interaction with AWT and Swing widgets should happen only in fe vats.
  ( Track this issue... )

• getOptMeta(brand). CapTP is now correctly using getOptMeta(brand) for opaque rights amplification so that a given instance of a CapTP system will recognize and see into its own remote pointers, but the remote pointers of another instance (or of a different CapTP-like system) will be as opaque to it as a local promise. (*** need to find email link)

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. A non-distributed E is called space-local if an object and all references to it only exist within its hosting process.

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 using code derived from the Cryptix library (in accord with the terms of their open-source license). In a space-local system, no distributed insecurity can arise, so such a system would be an sl-E rather than an sl-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.

This is the first "complete" release of E. "complete" is in quotes, because both the persistence and the distribution leave much to be desired, as explained above. However, these are close enough that this is the first release that doesn't need qualifiers in its name.

Dependencies

Versions & Types of Java

In refering 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 1.2.x.

This version of E requires a jre >= 1.3.1. E no longer supports Java < 1.3.1. To build E from sources, a corresponding jdk is required.

Some places to get 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 a version >= 1.0.

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.

Note: The website at the above link, http://www.lincom-asg.com/~rjamison/byacc/, seems to have disappeared. If you know where it may have gone to, or know how to contact Bob Jamison, please let me know. In the meantime, starting with the 0.8.10alpha1 release, the sources to byaccj are bundled with the E sources, and byaccj is made as part of making E.

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.