It's code that's been developed and it's been running for decades, I'm afraid.

How does that stop you from making a callgraph?

(On the off chance that you don't know what that is: http://en.wikipedia.org/wiki/Call_graph)

It doesn't. I was just answering about the code generator thing you mentioned.

100M lines of java code developed 'line-by-line' would make it one of the largest software projects that I've ever heard about.

Without telling you directly that you should disqualify yourself (after all I don't know you), if you don't have the knowledge about the tools employed to deal with medium sized projects (say up to 1M lines) how on earth will you deal with 100 times as much?

> 100M lines of java code developed 'line-by-line'

If it's not generated, then it may be "versioned" that way. I saw projects where the entire codebase was copied over to new directories tens of times, and no previous "version" was ever deleted.

But, after giving it some thought, 100 mloc is really MUCH, like in 50x more than anything I directly worked with. It does sound kind of improbable, but hey, it could happen :)

So ... is (some of) this 100M lines the output of a code generator which has since itself been lost? If so, then it seems like a good idea to take a good hard second look for it: scour every nook and cranny for source code, object code, documentation or any surviving evidence (old developer emails?) of how it worked.

Java was apparently introduced in 1995, and thus has not quite been around for "decades". Close, but 19 years is not quite "decades". LOL

Presumably somebody didn't write 100M lines of code on Day 1.

developed in java and running for decades? how long has the language been around?

19 years. But sun was pushing it quite aggressively at enterprises so it is not rare to see big java installations that are now 15+ years old.

And those are not the most fun to work on.

I started using Java in early '95 (having begged a copy from someone at Sun) and I seemed to be one of the first people writing stuff outside of Sun.

I started in August 1995 when I first heard about it, which I thought was when they released it but it may have had a variety of trickle releases.

I was working on something slightly similar (embedding a VM into a browser) during '94/'95 and was a bit miffed when I first heard of Java....

However, I did think Java was rather good and when I co-founded a start-up in mid '95 we positioned ourselves as a "Java company" - which was no bad thing in the long term as we were in a reasonable position when Netscape, Novell and IBM later decided they wanted to support it. Indeed our 2 round of VC investment was led by Novell - quite unusual for a UK company at the time...

I was doing Java in a very mainstream UK company in 1998; but we were leading edge and it became "standard" in 2000ish. By 2003 there were 100's of developers using it where I worked.