Is there something in the code? Rarely have I seen so many acquisitions -- and proposed acquisitions -- of software companies.

Maybe it's because tech is so cheap right now. Or maybe it's because the big fish are out of organic growth. Smaller fish can help when that occurs. Just ask IBM (NYSE:IBM), which last week agreed to a $5 billion deal for business intelligence specialist Cognos (NASDAQ:COGN).

But that's just one deal. At Motley Fool Rule Breakers, our scorecard has been twice visited by software buyouts. First, in May, Microsoft spent $6.6 billion on aQuantive. Then, in September, Cognos ate Applix.

Welcome to the circle of life in software.

And forget Black Friday. Oracle (NASDAQ:ORCL) CEO Larry Ellison shops all year long. His latest bid, a generous yet thus-far unsuccessful attempt to acquire BEA Systems (NASDAQ:BEAS) for $17 a share, has investors and the media buzzing over the potential for more deals.

Let's join the party. Here are three companies that could attract suitors.

salesforce.com (NYSE:CRM)
Potential suitors: SAP, Microsoft, and Google
I know, I know. All hail the master of the obvious. We've been talking about salesforce.com as buyout bait for years. And, in that time, software as a service (SaaS) -- "it's the end of software!" -- has become like Paris Hilton: overexposed but impossible to ignore. No wonder my Foolish colleague Rick Munarriz calls salesforce.com a stock to sell in 2008.

Yet this is an outstanding business that produces extraordinary cash flow. Behold:

Numbers in Millions

Trailing 12 Months

2006

2005

2004

Cash from operations

$161.6

$111.2

$95.9

$55.9

Capital expenditures

($42.8)

($22.1)

($23.4)

($4.3)

Free cash flow

$118.8

$89.1

$72.5

$51.6

Source: Capital IQ, a division of Standard & Poor's.

You should view this company on a cash flow basis -- any suitor most likely would. And on that basis, salesforce.com is no worse than fairly priced, as Fool Rich Smith points out here.

But as impressive as salesforce's free cash flow is, it's not what would attract a buyer. This is. Go ahead, click. I'll wait. With more than 35,000 customers -- some of whom, admittedly, are probably one guy in a garage -- salesforce.com has the greatest installed base in the history of software, and thereby, a built-in growth engine for anyone gutsy enough to bid the $7 billion to $8 billion it would likely take to acquire the company.

My best guess for a suitor is SAP, since Oracle has chosen to mostly eschew SaaS, and on-demand software doesn't require a database installation. But Google's July purchase of Postini gave it a taste of the gooey goodness SaaS can provide. Don't be surprised if it wants more.

Red Hat (NYSE:RHT)
Potential suitors: Oracle, Sun Microsystems
The Linux operating system is big business, and no one does it better than Red Hat. That's why Amazon recently partnered with the big fedora to offer on-demand computing power -- a move Red Hat says could put its software in half of the world's servers by 2015.

Compelling? Sure. Realistic? I'm not so sure.

What is certain is that virtualization is on the march, and that Red Hat is among the leaders of the parade. Why should you care? Because virtualization allows for processing power to be split into bite-sized chunks inside one computer. Think of a server that, on its own, can tackle jobs that used to take at least three or more. That's what virtualization enables, saving oodles of money in the process. It's also what makes the deal with Amazon possible.

Nevertheless, if anyone bids for Red Hat, I'm guessing it will be Oracle. Too many of its databases run on Linux, which, for now, gives it an edge over IBM in selling software applications. Expect Ellison to do whatever is necessary to protect that franchise.

Actuate (NASDAQ:ACTU)
Potential suitors: Microsoft, SAS Institute
Finally, let's talk business intelligence (BI). Cognos is gone. So is Business Objects, swept away by SAP last month in a $6.8 billion deal. That leaves only a handful of independent providers of BI: Actuate, MicroStrategy, and SPSS, to name a few.

I like top growth stock Actuate most for two reasons. First, its results are improving. Q3 earnings rose 83% -- easily besting Wall Street estimates -- and CEO Peter Cittadini is buying shares.

Second, the company is a longtime Microsoft partner, and Microsoft is the only major vendor of enterprise software not to have purchased BI expertise. Its Reporting Services software gets good reviews, but that's mostly a BI add-on to SQL Server.

Microsoft could bolster SQL Server, and thereby its position as a provider of enterprise software, with a tuck-in acquisition of Actuate for less than $1 billion. Heck, I wouldn't be surprised if deal papers were shuffling around in Redmond right now.

Do you have your shopping list?
We rebel analysts never bet on buyouts. But, if you're going to be a tech investor in this market, I think you have to know who's likely to win, and who's likely to be taken out. My money, not surprisingly, is on the leaders. But I also have an ample chunk of cash set aside for those that could change everything. (Hello, Akamai.)

What about you? Where are you investing when it comes to tech? And who's your vote for the Next Big Buyout? Let me know here. I'll publish the most interesting responses next week.

Till then, Foolish best and a very Happy Thanksgiving to you and your family.