F5 Networks ( FFIV) met analysts' estimates in its third-quarter results in July, although CEO John McAdam identified a cautious spending climate.

"It was nothing as bad as early 2009, but there's definitely some signs of caution ," added the CEO.

To illustrate his point, McAdam noted that F5's hiring remains robust. "This last quarter, we hired just under 100 people," he said. "This quarter, we're hoping to exceed that, probably hiring about 125 people."

With economic issues weighing on Silicon Valley, the Nasdaq has gained just 0.1% during the past month, lagging the S&P 500's modest gain of 1.5%. The Nasdaq has risen more than 12% this year, outpacing the S&P 500's 9.9% gain.

Not all tech companies are feeling the spending burn, as evidenced by strong second-quarter numbers from EMC ( EMC). The results marked the company's 10th consecutive quarter of double-digit year-over-year revenue and profit growth.

EMC storage rival CommVault ( CVLT) also posted robust results earlier this week, growing its revenue by 22%.

"The quarter was pretty well-balanced -- it started well and it ended well," CommVault CEO Bob Hammer said in an interview. "The momentum is continuing into this current quarter."

Still, CommVault is taking nothing for granted. "The assumption is that IT spending will come under pressure and we're attempting to mitigate that by making sure that our sales opportunity funnel increases at a faster pace," said Hammer. That could involve, for example, focusing sales people on very specific segments of the market and certain CommVault products.

In addition to storage, security and cloud are also hot technologies.

Security specialist Sourcefire ( FIRE), which is one of TheStreet's Breakout Stocks, beat analysts' second-quarter estimates on Tuesday.

Todd Headley, the Sourcefire CFO, said in an interview that the firm has largely side-stepped broader economic challenges. "We're probably small enough that we don't see the full effect of that," he said. "Even given the macroeconomic backdrop relative to the technology we provide, there appears to be a growing need for what we do."

Weak third-quarter earnings guidance, however, weighed heavily on the company's stock, pushing its shares down more than 15% on Wednesday.

Cloud specialist Medidata Solutions ( MDSO) also reported its second-quarter results on Tuesday, raising its full-year revenue guidance.

Medidata CEO Tarek Sherif shrugged off talk of a spending slowdown. "We're actually seeing quite the opposite," he said. "We had strength in Europe, and I think that really speaks to the value of what we're bringing to our customers."

Shares of the New York-based firm, which provides cloud services to support pharmaceutical and biotech firms' clinical trials, have gained almost 60% this year.

--Written by James Rogers in New York.

>To submit a news tip, send an email to: tips@thestreet.com.

Check out our new tech blog, Tech Trends. Follow TheStreet Tech on your wireless devices

If you liked this article you might like

Dow, S&P 500 Set New Records as Fed Moves to Unwind Balance Sheet

Cramer: Dominoes Are in Play Today

Stocks In Negative Territory as Chances for December Hike Surge

Caterpillar Leads Dow to Records, S&P 500 Also at All-Time Highs

S&P 500 and Dow Score Records With Wall Street Upbeat Ahead of Fed